Reading the forums, I removed anything on both the USB ports, now relying solely on the USB-c adapter. So far seems ok. I may just have to buy another adapter, and just block those 2 USB ports.
Yet another issue for me ... those pink squares blinking on the screen ... https://discussions.apple.com/thread/252076087
Are you using usb c and hdmi? I was having an issue with usb c not displaying until the login screen. So had to use hdmi 2.0 in your case, I assume dual 1080p monitor. The soiution for now is both usb c connection for both. Or a dongle that supports dual monitor output.
I'm using one 1080p monitor direct to the HDMI port, not on adapter. The pink squares don't show up all the time, and if they're there, I'd open any app and "sweep" the squares, and they disappear. My other issue now is the long boot time. 48-50secs, like booting Windows on an HDD.
Wow if it were me experiencing those issues, it would drive me nuts. Haha anyway contact apple support asap*
Since owning a Mac in '06, I've never ever called Apple for support, even if I had AppleCare on those units. Mahiyain kasi. Hahaha! I just check all the forums and usually nahahanap naman ang issue. Or do all the experiments I can. First thing in mind is a clean reinstall of Big Sur. (Ops, I once had my Air's battery replaced, thru the vendor.)
The Mini resolved this issue by itself. When I woke up this morning, I was surprised boot time was just 18sec. Tried it a few times, still consistent. Before this, I was already thinking of doing a clean reinstall of Big Sur.
Was able to use my old apple 27” LED Cinema display using a Mini Display to USB-C adapter from Lazada
