Seems that I'm not able to edit my previous message, so:
I reconnected the fuses one more time, deleted my account both from the car and the skoda app, changed key batteries etc. and went for a short drive. After that the car got connected again and I was able to log in. Everything seems to work normally now.
Airbag light still exists. I probably have to ask the official skoda service partner to reset it..? There's no real problem with airbag tho, or at least the car or the MySkoda app's healt report says nothing about it. Only the notification when powering on.
