MacbookAir Screen turns off randomly

Hello together, the screen of my MacBook Air 2020 with M1 Chip turns off randomly sometimes. Sometimes (not always, in other scenarios it just starts without a "warning") the problems begin with the screen flickering (picture) and showing a projection of everything on the screen but just misplaced and a little faded (for example, the apps in the dock can be seen right under the phrase "JETZT IM CINESTAR"). These kinds of screen errors then get a lot more frequent until the display but only the display and not the whole Mac turns off. I am still able to type, sounds continue and an extern display does not show any faulty behavior. Waking up the display with the keyboard or trackpad does not work, only if I close the lid for a second and open it again, the display turns back on, but only for around 5 seconds before the problem repeats itself. This then goes on for 30-50 Minutes and makes the MacBook unusable. I have tried installing BigSur to exclude software errors from a new version but it didn't help, also a complete clean reinstall did not fix the problem, neither did clearing NVRAM or the starting in safe mode. A Hardware test state everything would be fine and the lady in the apple Store couldn't help either, so I am wondering if anyone else was experiencing the same problem!? And has found a solution to it...