Apple has announced that it’s aware of the pink square glitch occurring on the M1 Mac mini and says that they’re working on a patch to fix the issue.
The ‘pink square’ glitch is a row of pink boxes that appear on a display. M1 Mac mini owners have taken to social media and the official Apple forum to complain about the issue, and they’re finally heard.

Troubleshooting reveals that the issue only occurs in displays connected via HDMI, not Thunderbolt or USB-C and is regarded as temporary. In some cases it’s a matter of turning the display off and on again, or switching audio sources out the portable computer.
Apple has not issued a statement at this time but the company is working on a fix. However, a timeframe was not given. The Cupertino-based company will most likely release a minor update or integrate the fix within a larger release software.