Underfloor heating air-water heat pump. House too warm when the sun shines

Could you please write down the rooms per floor, all of them, each with room size and number of heating circuits.
Do you have only underfloor heating in the bathrooms?
If you don’t mind, also the floor plans of the floors.
The model of the heat pump should be told to you by the heating engineer. Interesting are the heating output of the heat pump and the heating demand of the house.
What is your current total flow rate?
More information would be good

Sure, gladly, floor plan pictures attached. The hobby room is the basement of the carport. There is also underfloor heating there.
All rooms have 1 heating circuit except living/kitchen has 3 and bedroom/dressing room 2.

In the main bathroom we also have an electric towel warmer.

Where can I see the total flow rate?

Total flow rate = sum of all heating circuits, simply add the readings of the flow tubes at the HKV. Then compare again with the flow rate specified by the heat pump.
under Settings-Informations-Inputs (I think)
The tubes from the living room look so cloudy...

I'm a bit confused. Is the bedroom/children's room upstairs? What is then below the bathroom? Good that you have an electric towel radiator in the bathroom and it's not connected to the heat pump. That way you can heat independently if needed. Otherwise, I'm considering: One heating circuit per room, so on average about 14 sqm per heating circuit? That means either large pipe spacing or heating circuits over 100m long. I would have to calculate that when the children are asleep. Both would be unfavorable. Long heating circuits mean high pressure drop from supply to return. Wide pipe spacing means low heating output per sqm. Neither is optimal. Two heating circuits in the bedroom on 18 sqm naturally means significantly more heating output than one heating circuit on 15 sqm in the bathroom. Also many exterior walls in the bathroom. That already explains why it is too warm in the bedroom and too cold in the bathroom. Didn't the heating engineer have a calculation to base his work on? He should then give you that. But it is what it is. You have to consider now, either leave everything as the heating engineer set it, then the heat pump will probably keep cycling and be broken by 2030 at the latest, or you take matters into your own hands. It's complicated at first, but ultimately not rocket science. You just need patience for the first few weeks, after that it's just fine-tuning. I know, with a child there is no time and peace, and when the child is asleep you can't anymore. I can support you. Where is the house located anyway?

Do you have a slope?

The main thing is that the short cycling stops. Consumption +30% would be better for me than a dead heat pump after a few years.

Hey, we built in the Hang, the ground floor is living/dining/pantry, study and a small shower-WC.
In the basement is the main bathroom, parents' bedroom, child's bedroom, guest room, and utility room. And then we also have the cellar under the carport, so to speak our storage room.
Above the bathroom is partially the balcony, the corner that sticks out like that.

I will write to the heating engineer directly to ask if he can send me the calculation of the heating circuits. I'm curious...

It is really very kind of you, of all of you, how you support me. For me, unfortunately, it is really a kind of rocket science, I had 0, nothing to do with something like this so far, I find it totally complicated. :-(
But I am feeling my way forward, thanks to your or rather all of your help.