External display signal issues with M1 Max on 13.2.1

[gammamonk]

This week I've been having a nightmare of a time with external displays. I'm connecting via USB-C to a 4K monitor (different models at work and home) and I'm getting random signal loss, weird artifacting, and most frustratingly I can't use any apps in full screen.

At work on an LG 4K monitor I'm getting random flashes of solid white which is really jarring. At home on on an Aorus 4K I'm getting random complete signal loss, but also 100% of the time if I full-screen an app (even as simple as a Terminal) the external monitor loses signal and I have to reconnect it and set the scaling and arrangement back up.

It's a 2021 M1 Max 16".

What is going on...

 

[fried_gauss]

Same here. I am using two BenQPD3220U displays and if I have something black on one of them for too long, it starts flickering randomly and it’s super jarring. What I have noticed is that if I activate my screensaver, the screen has zero jarring in that state and so it only appears when the OS is running its normal screen. I have had to use my screen in light mode, but I spoke to BenQ support. They are aware of apple silicon macs having issues with external monitors

 

[snillemikke]

I have a 2019 Intel iMac, and I too have recently gotten external monitor issues like you're mentioning...

 

[gammamonk]

FWIW I switched over to using the HDMI port on my MBP and that seems stable, but it's a huge pain. I can't use the the monitor's built in USB hub and it won't go over 60hz and I have to charge the laptop with a separate cable... /sigh

Checking for macOS updates daily...

 

[gammamonk]

I updated to 13.3 yesterday and so far no problems. Fullscreen works again, no flickering, no signal loss. 👍