After I lock desktop there is no way to wake it again.

(Already posted this in the wrong place, hope this is the right one. This seems like it's not necessarily elementary specific, but I have no idea how to start troubleshooting, so an advice on that would be great and I can close the bug. There are multiple posts on stackexchange also about this problem with few or none answers :( )

Problem:
I lock my session. After it is locked there is no mouse movement or keyboard tapping in the world that makes the screen turn on and show me the login prompt again.

Setup:
ElementaryOS 5.1.3 Hera
5+ years old MacMini

Obv this makes EOS quite shitty for me atm, since i care about security :(

Please advice me on how to provide logfiles etc. to try and troubleshoot where the problem lies.

Last note; I have prior connected a second display to this system, but the problem persists with the second one being plugged in or not. I also THINK that the problem existed before I connected a second display, but I am not 100% certain.

Thanks in advance! :)