iOS 14.5.1 no service(no signal, no cellular data)

Hi!
I've installed iOS 14.5.1 on my iPhone 8 plus and since then, I lost the signal and I don't have data. I have an Android phone, and my sim card works well with it.

I tried many things like:
Turn off/on cellular data
Turn off/on airplane mode
Turn off/on roaming
Hard reboot
Soft reboot
Reset network setting
Reset all settings
Erase all contents and settings

...
Same issues

Do you have any idea how to fix it?
My iPhone 8plus comes back to normal tonight. Very interesting. How could this happen?
Having exact same issue with iOS 14.5.1. Says that phone has No Service to Verizon every morning because iOS needs to be upgraded, even though it is already current with 14.5.1, confirmed by WiFi connection. Have had auto update on as well as off and still comes up No Service daily. Have to soft boot 3-5 times to eventually connect to network.
And it goes wrong again since this morning.

Mine started this morning - Received an SMS message while on cellular network on my way to work. Picked up the phone to look at the message when I go to my office and had no signal and it just keeps searching. The signal here at my office is always very good. I headed toward the AT&T store to ask if there had been any issues; got another text on the way so I turned around and headed back to the office. Same result. Arrived in parking lot and the signal disappeared. Others in the office with the same AT&T service are surfing along on the internet and making calls. I got squat. I have no idea why it suddenly just stopped getting a cellular signal. I've tried rebooting, changing the roaming setting, cellular setting, wi-fi even (but we don't have wi-fi here). I have 14.5.1 installed on the iPhone X.

Anybody got any ideas on this?

iOS 14.5.1 no service(no signal, no cellular data)
 
 
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