Adjust underfloor heating - defective?

I turned counterclockwise at the spot where the screwdriver points.

That doesn't help. It should simply be firmly turned clockwise. That is the mount for the actuator.

The red parts at the bottom cannot be turned, only the white plastic around them.

The white is just the scale; it can be freely rotated. It is not the red part that needs to be turned, but the glass. That’s what the square drive on top is for. Can the right one really only be turned clockwise? Additionally, there is a square drive on top around the pin. Made of brass. That is where the flow is actually adjusted.

The bathroom is warm again, woohoo! Thanks for the help. Now the heating still needs to be properly adjusted but at least I am relieved that the underfloor heating in the bathroom still works.