Thanks, I thought so. But the issue remains, the wifi won't work anymore after a few restarts. Or when entering into Kodi it suddenly stopps working. I have to reset it manually, sometimes once every 2 weeks, sometimes with each restart.

I have the same issue again and again, the password ist suddenly altered to something else, looks like encrypted but could also just be some cache overflow? sometimes it starts with "enc:" followed by 44 random chars...
After overwriting with the correct wifi-key, it's currently sufficient to exit and re-enter the menue and the password is altered agin. It is impossible to continue like this, so i will have to re-attach it to a cable
Maybe when changing the config-file manually it works again.