El. window lifter at 88 C1500, who solves the puzzle?

Hi! My window lifter on the passenger side has been having problems sporadically for a long time (he once went, sometimes he didn’t go). Just now he completely failed his service. I describe the problem: the window is currently half open. Both from the driver side switch and from the passenger side switch, the window can be opened even further, but no longer up! This means for me that the engine in the passenger door is not defective. At the switch it won’t be lying either, since I have now taken down the door panel and tried to unscrew the sheet metal behind it. However, I have to find out that the window lifting mechanism is riveted. I don’t really believe in a mechanical defect, because it can be opened further. Is there a relay somewhere for “open passenger side” or something? That maybe only that is broken? Everything else goes well. So, and now here with the n Tips…is currently glued off with foil, because of course it has to start raining right now… Greetings, Lukas.