ZV: Test the process

Hi everyone!
I've recently been having a problem with the central locking system (on my 1998 Passat B3). I had window tint films installed on the front side windows two weeks ago. Apparently, some water has seeped into the door as a result. Since then, the central locking system has been malfunctioning; it can no longer be operated from the driver's door (using the key), and the window/folding mirror function is not activated. It does work via radio frequency (aftermarket Conrad system). When it's hot and dry for 3-4 days, everything works fine again until the next rain. Does anyone have any tips on what I can do? It doesn't seem to be completely broken .
Best regards,
Alchard