Monterey Beta 8 - problems with external display

After updating to Beta 8, I can't seem to get my external display to work. The backlight on the monitor turns on and it seems to interpret some data from the MacBook briefly displaying a flash of colors and then going black with the backlight still on. The Display is still fully function on a different Mac.

Macbook Pro 2016, display connected to external thunderbolt 3 hub.

Answered by IgnacioAF in 689793022

As a workaround, I installed Beta 6 (complete pkg) over beta 8 to restore my display use. I guess the solution will be in the next beta (9).

I have seen the same behavior, my LG UltraFine 4K display just stays black and it is directly connected into the Mac Thunderbolt port. From what I have seen in other discussions, this seems to be limited to Intel based Macs and is a new bug in Beta 8 (M1 based Mac's seem not to have this problem). I have filed a bug report to Apple and hope they get it fixed as quickly as possible. It feels so strange to depend on the built in display and only have one display available and have the big black screen right in front of me.

I had tried resetting NVRAM and SMC and no change, monitor still stays black. Also connecting original power supply is not making it work. Interestingly, USB devices connected to the monitor all work and the monitor shows up in the system report as connected to Thunderbolt / USB4 but it is not recognized as a Display device in the system report nor the system preferences. System preferences only has the internal display available.

Yep, identical description and issue. Thanks, let me know if you hear back on the problem report.

Yes I will post here if I should hear anything back from Apple. Well the big hope is that we will get a new release latest next week with this hopefully being fixed. Let's keep fingers crossed.

Identical description for me as well... that's what betas are all about, they say. Let's hope we have a fix sooner than to expect another beta release, maybe a patch file, a workaround or even a new version of the same beta.

Same here. I cannot work without external displays... I'm in depth trouble here :(

First display (Thunderbolt Display) doesn't show up in system report, yet it displays boot information on it early on in the boot process. The second display (thunderbolt to DVI) comes up as the login screen. Since the primary doesn't show up in the "System Report" it feels like something broke in device discovery and enumeration. (2013 Mac Pro trashcan). Worked fine in previous betas.

Plugging in with HDMI to USB-C works for me as a temporary fix with my BENQ PD3220U. Hopefully a fix will come soon.

same here MacBook Pro 2016 with a Samsung 4k monitor no matter the connection (display port hdmi) it stopped working and of course in another Macbook 2016 with Big Sur the external monitor works

Got the same thing happening with a 2015 iMac + an external Apple display.

Got the same problem with Mac Pro 2013 version and AOC 4K Display.

What I find interesting about this is that I have 2 MBPs (2016 and 2020 both Intel) and the 2020 is working as expected but the 2016 is not. I don't know what that means in the big picture, but it is not widespread on all Intel Macs. Good stuff...

Same with Benq and Displayport.

Accepted Answer

As a workaround, I installed Beta 6 (complete pkg) over beta 8 to restore my display use. I guess the solution will be in the next beta (9).

Same issue here - my trackpad also stopped being recognized

I just installed Beta 12 and the problem with external monitors continues, at least in Intel models.

Monterey Beta 8 - problems with external display
 
 
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