Air does not flow out of my central front air vents Mk1 93

Hello.

When I select the front direction on the interior heater/cooler I’ve noticed for a while no air (warm or cold) comes out of the front central vents. Only from the bottom and maybe from the top. Furthermore, the cold air isn’t really all that cold but warm (even today).
The blower is working but does this mean the cable from the heater is not working or a flap is stuck?
How to fix? Take the dashboard off and look at this? this also happens on either fresh or recycled air settings.