2009 VW Passat 1.4 TSI: power window goes up then comes back down

Hello everyone.

We have a 2009 VW Passat 1.4 Tsi petrol.

I have a problem with driver power window. When I press the window button in the up direction to raise the window, the window slides up to the top but then slides back down again - not all the way, most of the way. If I keep pressing the button the behaviour keeps happening except eventually it slides all the way back down. When this happens pushing the button in the up direction does not raise the window at all - it has no effect. Eventually after a few minutes the button starts to work again but the behaviour with the window going up and then down persists.

In order to get the window mostly closed I push the window button in the up direction very briefly in order to raise the window slowly in small increments until it is very close to the top at which point I stop. If at this point I keep pushing the button in up direction until the window hits the top then it will just roll back down again.

The window was working fine until this started happening. Any idea why this is happening and what I can do to fix it?

Thanks.