My Jolla is telling me a few times per day, that my SIM card was removed and supposes me to reset the device. Will something wrong happen if I solder the contacts of the SIM card slot so, that the phone will detect that there is always a SIM card inserted? Dose Anyone have already done this on his phone?

had similar problems with on of my sim cards. Especially when I kept the phone in the back pocket. I got the impression that the sim card looses contact when the phone is bended too much.

Maybe it helps if you put some sollotape on the back of the sim card in enhance the contact.

Hope this helps
Bye Jo

Had same issue and sent phone to be repaired. There's a design flaw in sim card slot

I've inspected the SIM slot and I can't trace the contacts which I need to solder to simulate that there is always a SIM card in the slot. Anyway, my problem is solved for now. I have a qwerty OH. This OH protects the SIM slot and now I don't have the SIM reconnecting issue. But if remove the OH and touch the SIM/or SIM Slot, the SIM Card error appears immediately!

It's not about the contacts, don't bother soldering those. Problem is the micro switch that detects if sim is inserted. You can try to jam that switch to workaround the problem.