Air vent problem

[Johnboy]

I have a 2017 Cali Beach. When bought from new there was a problem with the air conditioning which involved replacing a broken actuator strut somewhere in the bowels of the dashboard. Said strut was cracked at one of the pivot ends.

The problem was rectified by VW and I happily went on my way - mainly using the Air-con on auto and not really bothering about all the other bells and whistles. Much later I was aware of another issue which I never did get fixed, and I still have it today. My central vents in the dash do not function........ I can open them with the twiddly knob at the bottom and feel a very small amount of air passing which stops when I close the twiddly knob (so that bit is working). So when I press the button for the dashboard air and turn up the fan, I get a real blast out of the side vents, and nothing from the central vents.

Also the windscreen and footwell buttons also direct a full blast of air when pressed individually, but if I turn off all three (i.e windscreen, dashboard and footwell) there is a short pause and then the side vents come on full.

I am wondering if I have another failed strut (or something similar) and that air is never getting directed to the central ducting.

Anyone else had a similar thing and any suggestions how to fix it?

Regards

John