Mac Mini M1 won't wake display from sleep using DisplayPort

I've been having the issue that my Mac Mini M1 won't wake from sleep. I also sometimes get the purple squares when I first wake up the computer (by unplugging and plugging the DisplayPort cable!).

The solution I found was to remove the DisplayPort cable and replace it with a standard HDMI cable. Both problems have now gone away. It wakes from sleep every time now (using logitech 2.4ghz wireless keyboard and mouse) and I no longer have the issue with the purple squares appearing.

However, I find it very poor that this issue has been known for at least 5 months - and Apple has not fixed it.