Can no longer detect 2nd display in MacOS Monterey

I have the same problem, using original Apple 24" expensive displays - why is Apple hiding such a significant problem - I am really disappointed with you guys :( - The problem has existed for more than SIX months !!!!!!

Just updated to Montery 12.4 and still have the same issue. External monitor not recognized-no display options to find in preferences. Need apple to weigh in on this. I have a 2015 macbook pro connected to an external monitor with thunderbolt and hdmi. neither work.

I use a Mac mini 2018 intel for design work. After updating to Monterey 12.3.1 I lost use of my 2nd display that is connected via HDMI cable. The display connected by USBc does still work. I switched the wires and the same thing, only USBc connection worked. It is not a problem with the monitors it is caused by the upgrade. I spent multiple days talking to multiple apple support advisors, even the ones at the highest level and no one was able to fix this problem.

If you are able, downgrade to Catalina. I was able to do this by backing up my computer first on an external hard drive. Then deleting the hard drive so it reverts to manufacturing settings. I was on MacOS Mojave 10.14.6 and the problem goes away. Then I upgraded to Catalina and my 2 displays were still connecting. My mistake was upgrading to Big Sur like the apple supporter advised me to do. Once I upgraded to Big Sur my 2nd display was not connecting again. This was the original problem. I figured I can go back and repeat my steps and stop at Catalina, but for some reason (no one could help) I was not able to. I kept only getting the option to download Monterey which was the original OS that caused the problem. So I am stuck only using only one display.

The only advise I was given was to talk to the manufacturer of the displays to see if there are any updates to the drivers available. That's right, blame it on the displays that aren't mac.

Are Apple developers at least aware of the issue? This bug seems to affect many users and the impact is pretty significant. I don't understand why this hasn't been fixed for 3 minor version upgrades (for half a year).

TLDR: Try connecting to a variety your TVs? Seemed to fix the issue for me.

I just updated my 2017 MacBook to 12.4 Monterey last night (May 20, 2022). I thought that I had waited long enough for Apple to work out all kinks, but I immediately had no ability to detect my second monitor, which brought me to this thread here.

I went through the basic troubleshooting steps and was incredibly frustrated because one of the simplest options mentioned didn't even work (hit the option key to switch the Night Mode button to Detect Displays).

As an additional step I decided to try connecting to one of our newer smart TVs. Although the USB-C to HDMI cable didn't work, I was able to connect with AirPlay.

I decided that before I unload I bunch of money on a new monitor that can use AirPlay, I thought I'd try connecting to my oldest TV (15 year old Sony with an HDMI port but no wifi or bluetooth) and maybe move it into my office if it worked. OMG, now the HDMI cable is working! I took it back to the original monitor and BAM! Connected with no problem.

So, I have no idea why this worked, but it did.

I had this issue suddenly start after using Monterey for a couple of months. The Dell USB-C monitor couldn't detect the source, although all of the USB ports were working. The only thing that solved this for me was to remove the power cable (physically) from the monitor and reattach

None of the solutions I've read here work for the 2022 Macbook Air. The first monitor plugged in wins, regardless of which of the two ports is used. Detect monitors, powering on and off, sleeping and restarting, none of those make a difference.

All of a sudden experiencing the same issue which has lead me to this thread. My macbook seems to definitely notice something is plugged in, because the mouse slows down when the monitor gets plugged in. What an absolute nightmare. Stuck working from home with covid and now can't even get my work done. Pulling out power cord is not working for me.

MacBook Air (M1, 2020) Running 12.4 Will not connect to LG 38**95C-W.

I suspect that there is something wrong with the Mac USB type C ports. This display works with a Ipad pro and same cables (its the only other device i have to test with)

Here is a recap of my experience with the M1 Air and USB devices quickly.

1. I Love the idea of having only one cable, so I make sure that a monitor would be able to use USB C. The first monitor I bought was a gaming monitor, and the monitor at first worked but then would not output sound. I reached out to Apple support and got the runaround - this was a less well-known brand, so I returned it. ** Major Issue with my customer support case here** My computer was brand new at this point also
2. I Bought an LG 34 in a monitor for a home office worked great - I bought a second for a remote Office again worked great, with no problems.
3. I Moved and left my old monitor at my old place for when I was there. I upgraded to the 38 In Curved- again, no issues for about six months, occasionally issues waking up the computer but nothing that I was concerned with. and then finally, No output. The monitor is detected when you plug in for a few seconds, but nothing shows up, and then the monitor displays no signal. Also, the top (closer to the monitor) thunderbolt will not even have a few seconds of recognition.

** The Thing that frustrates me is that now I am out of apple care warranty and suddenly having USB C issues again as I had with the very first monitor. And when talking to Apple support at that time, I was very adamant that I wanted to ensure nothing was wrong with the USB C port on my computer(I was coming off a couple of incredibly frustrating apple care situations, so I was overly cautious). They assured me it must have been the monitor, and they were kind of insinuating that not all companies make the best hardware, and I should not buy cheap products. Since it was a less well-known brand, I took their word at the time ( it was like scepter of something I can not remember - which worked great with a windows USB-C connection). Now I am out of warranty, and it is looking like I am not the only one with this issue. Apple support has been worthless once again - and it looks like I was probably correct way back when I first got the machine that something was wrong or at least "buggy" with their thunderbolt ports, but apple did not care then, and they don't seem to care now. O man, I miss the old days when you could walk into an apple store and be treated like a human RIP

I had the same issue and tried everything listed here. I even went to the Apple store and tried my computer out on their monitors. After a lot of searching, I found the problem. This does happen after upgrading to Monterey and it related to graphic card switching (at least for me on my 2019 Intel-based 16" MacBook Pro. To fix it, go to System Preferences - Battery - Power Adapter (left side)- then turn of "Automatic Graphics switching". I swear I was pricing new laptops when I stumbled on this. You're welcome

I picked up a new Mac Studio in March. It has no problem detecting my 3 brand new Samsung monitors but it can't remember the monitor set-up. After waking up from sleep, logging in and out of my photoshop login, and restarting, the Mac Studio persistently forgets which monitor is landscape, which is portrait, which monitor is the main display, and the arrangement (24" landscape on the left, 28.5" landscape in the center, 24" portrait on the right). It also loses the color profile and refresh rate. Sometimes it remembers settings for a few days but then it loses everything again and I have to begin the day by painstakingly restoring the set-up.

The situation did improve considerably when I installed Monterey 12.4, bought the new Apple keyboard, and activated touch ID. At the same time, I also rearranged the brand new USB-C cables from the monitors into the 2, 3 and 4 Thunderbolt slots on the back of the Mac Studio. I have found that I can "fix" the problem when it forgets the settings of the two external monitors by switching the USB-C cables from slot 2 to slot 4 and slot 4 to slot 2, putting the Mac to sleep, and then waking it again (hey presto, back to normal). However, the whole thing comes crashing down if I remove the main monitor cable from slot 3 (to use it as an external display for my MacBook). I do realize this makes no sense because the Mac Studio should be oblivious to the order in which the monitors are plugged in. However, IRL that doesn't seem to be the case. The Mac Studio wants the main monitor in the middle between the two external monitors.

I love this machine. I came up from a 2012 iMac so getting a Mac Studio is like moving from impulse drive to warp drive. Since I discovered the slot-switching trick I'm spending half an hour a week on the problem instead of half an hour a day. BUT it's still a real time sink and disruptor to workflow. I wish I understood why there is no "Save these settings" button in Display preferences.

I have a Mac Studio. Before 12.4 I could use 2 HDMI monotor's without any issues. One through the HDMI output and one using a USB-C to HDMI dongle. The monitor using the USB-C HDMI dongles is no longer detected. Have tried everything in this thread but it will no longer work.

I had this same problem and solved it like this:

1. I normally connect to my second display with a USB C cable. It was this display that could not be detected.
2. I got an HDMI cable and with an adaptor connected it to my iPad.
3. Having a second display connected meant that when I was in System Preferences - Displays, holding down the option key resulted in the "Night Shift" button finally changing to "Detect Displays" and clicking this button resulted in the monitor connected with the USB C cable appearing.

Apple should update the OS so that "Detect Displays" is always available.

Very strange workaround (dell 32 usb-c):

1. turn off the monitor
2. open the laptop lid
3. turn on the monitor
4. close the lid

have to do the same thing every time MacBook is restarted. Very annoying.

Ive already planned to switch to Windows this fall, If this is not fixed. I am 39 years old and so just need a good productivity workflow. It seems Apple is playing dirty games to try to convince people to switch to Studio Display (I went to Apple store and guess what, it works fine on studio display). Coincidence?

No luck on 13 beta "Ventura." They should start naming these versions "Probably going to break some core piece of functionality."