Some customers who have purchased an M1 Mac mini have been experiencing an issue that causes the machine not to wake a connected third-party display from sleep.
This is not an issue that’s affecting all M1 Mac mini owners, but there are numerous complaints on the MacRumors forums and the Apple Support Communities dating back to November when the Mac mini was first released. MacRumors reader gooimac explains:
My M1 (8gb/256) Mac mini doesn’t seem to want to wake my displays after its been sleeping. I have tried with 2 different displays with 2 different HDMI cables with the same thing occurring on each one. I am currently only using one at a time. I also noticed some pink squares/graphics glitches on the Big Sur boot/log in screen (with the coloured background, not the black and white boot up)
Read more at MacRumors.com