I have had the same issues with flickering with my M1 Mac. I have talked to apple and have a conversation with them set for tomorrow with a senior advisor.
I thought it was the DL problem but it turns out to be a Big Sur/ M1 / HDMI issue.
You can read about it here.
https://discussions.apple.com/thread...022&login=true
Also I don't know if this is related but my displays are out of order upon wake from deep sleep.
Anyone else having that problem?