Did you remove the back at all right before this happened? If so make sure the CM is fully seated in the adapter. It sometime pulls out when removing the back.
Did you do a dist-upgrade of some kind on the distro you’re running? If so you replaced the custom kernel with the distros stock one that doesn’t include the drivers for the device. In that case you need to manually replace the kernel with a custom one or reflash the SD.
Just take another SDcard, flash one of the various images provided by @Rex and try to boot. This way you can easily rule out hardware issues. If the Problem persists, then check the hardware.
Well, with the another SD and one of @Rex images all seems to work fine again. Thanks for the suggestion.
Looking in the bash history from the old card I only see that I tried to install adn setup wireguard VPN after that I turned off the console and problems started.
sudo apt-get install jq openresolv wireguard
Not sure how this can break anything…
Luckily the old SD data is still there so I can copy all the files.