Air-water heat pump combined with underfloor heating does not work properly

Every time as a layperson, I am surprised that apparently you have to have studied to operate an air-to-water heat pump (-:

If I had known that, I would have chosen gas; the 10 euros more per month would have been worth it to me, so that I would simply have peace and could just turn it up during the transition period …. I am a woman and it is practically unbearable that the heating doesn't turn on because of some hysteria blah blah (says my husband) … On the ground floor I turn on the stove, in the bathroom I freeze (-: Women, you know …

Do you have the lengths of the heating coils and the heating load of the individual rooms?
On the internet, there are calculators or formulas with which you can calculate the (rough) flow rates. Then you can roughly check whether the Homematic is working correctly.

I know the company, we had the radiators in our old apartment equipped with wireless thermostats from them. That worked quite well.
I cannot judge how the heating actuator works. I haven’t read it in detail either, only something about continuously regulating flow. To achieve that, you would either need actuators that can do that (rather rare) or the actuator regulates it via something like pulse control. No idea, I’m not technically familiar with the details.
The question is: Do you need that?
To make the whole thing controllable, you usually need an access point with Homematic. So you'll spend another 300-400€ on devices that, in turn, consume power and can break. A thermal balancing is not rocket science. It costs you a bit of time during one winter, but that’s it. If you do it right, you never have to touch your room thermostats again.

I have KNX installed. I integrated the actuators into KNX (this happened for various reasons, not because I said I needed it). So I could program any nonsense there. That on the third full moon of the year, with more than 4 hours of sunshine before 4 pm and more than 1.5 m/s wind from the southwest, the temperature in the living room is raised by 0.5 degrees, but only if someone is present.
And do you want to know what I did? One winter season of thermal balancing. All actuators are always fully open, the rest regulates itself. Maybe I have to fine-tune a bit this winter (2nd season in the house). But so far totally hassle-free. Now that it’s gotten cooler, the heat pump started by itself and sure enough, the temperatures are +/- 0.3 degrees as I adjusted last season.

Yes, there are indeed a few nuances. When the sun shines a lot, it’s very windy, etc. But you can’t regulate that because the system is too sluggish.