Despite the Mac mini M1 being an awesome fast machine it seems a lot of users are facing the problem of no image waking system up of sleep
In my case I use 2 x LG 27UL600-W and the one connected thru Thunderbolt cable ( the port in the computer doesn’t seem to be important, same issue ) 2/5 times doesn’t wake up.
only solution working was plugging it out from the back of the computer and plugging it back in until now
Yesterday I had the idea to try to put it back to sleep using the working monitor and waking up again after a couple of seconds seems to work flawlessly.
for those with one monitor you can setup a keyboard shortcut to put it to sleep in blind and see if works for you also () as suggestion of MaitreMailin to my reddit comment here