Folding wing mirror issues

They should both fold when the control is turned to the fold position.

They do not fold automatically when you lock the car, only manually using the control. Though if I remember correctly, retrofit king NHN did have a go at creating a circuit to automatically fold the mirrors on locking, but I'm not sure how successful he was.

I do sometimes have some niggles with mine. Sometimes they don't do as they are told (Not folding/not opening/only one opens) but a bit of a faff with the control and they come back to normal operation.

You may have a duff motor in the non working side. Scanned with VCDS for fault codes? Only way to check is to see if an output test is available with VCDS, failing that you are getting into the realms of checking for feeds/earths/signals to the motor.

Both should fold and unfold together. They only fold with the button. I believe there are threds on here where people have tried to get the mirrors to fold when ignition is off and open when ignition is on but I don't know if anyone has managed to do it.

Ash187 has his so that they fold on lock and unfold on unlock. It's a custom wiring job, and an not easy one judging by what Ash said to me.

Sounds like you need to get a VCDS scan done to see if your door modules are bringing up any errors.