Polo Central Locking Problem - Help please!

[krobbo]

Hoping to find some help on here since I can't find anything with a google search.

For a while my 2003 Polo has had a quirk with it's central locking - when I press the lock button in the cabin all the doors lock but then the passenger door unlocks itself straight away.
The passenger door also unlocks itself if you door a scenod door lock from the outside - i.e. if you turn the key to lock then turn to lock again the passenger door will then unlock.

For the first time I tried the passenger door lock and when turning the key only the passenger door locks, the central locking is not activated.

Anybody got any ideas? As I said, I can't find anything similar anywhere online

[S0 What]

If they are anything like the golfs of the same age the soldering on the circuit board for the microswitches in the lock mech crack and causes all sorts of issues, with cycling C/L and windows opening and closing.

[krobbo]

Thank you, that's not something I ever would have thought about.

So how would I go about fixing this?