Well, I opened the OpenSpot4 again and took the contact loose and refitted it. Maybe that will just do it.
For now I had to reconfigure the device-settings as they were lost in the reboot.
No big deal, just had to set the wifi, country, callsign (DMR number is given automatically), connectors for DStar and the APRS settings. So far it seems to work fine. I just don't dare to shake it, hihi. Okay, did just that and it works just fine. Power off/on repeatedly works. I'll handle it with care.