Questions about underfloor heating with geothermal energy

I don't want to bother you every day, but this cannot be right!

This morning it is 18.4 degrees here in the living room!

System settings at an outside temperature of 8 degrees:
Circuit 1
Heating curve 21.9/36.3
T1 flow temperature 24.6
T1 flow target value 26.9
Room 35.0

Heat pump 1
T6 heating gas 23.1
T8 heat carrier out 24.7
T9 heat carrier in 24.7
T10 floor circuit in 15.4
T11 floor circuit out 15.7

The room thermostats in the living room and bathroom are set to maximum.

Since I (still don't) understand values, I wonder why the system is not heating at an outside temperature of 8 degrees. Why is it not heating when the target value is 26.9 but it is only 24.6?

Does your heating run all day or are heating times set? For us, the heating runs at night, in the morning shower times are set and then we leave the house. In the afternoon it starts heating again. In the evening there are shower times again. Hot water is always heated with priority, have a look at the times for hot water preparation.

Also, I am surprised that you have set a flow temperature of 26° and a room temperature of 35°. You can never reach 35° with 26°.

Perhaps a nighttime setback is set on your system? Unfortunately, this is often done in the default settings and actually makes no sense in new buildings with heat pumps.

No night setback and no shutdown during the day. I'm already surprised because the curve indicates that at an outside temperature of 10°, the flow temperature should be 26. But then the living room with the thermostat turned up should offer more than 18°, right? Why is the flow temperature lower than the flow setpoint temperature? Am I misunderstanding something here?

To Musketier:

Even if I were to lower the [soll-Raumtemperatur], nothing here would get warmer. The mentioned 26° are not even reached.

How do your settings compare? I don't want to leave anything untried.

What does the hot water preparation do?
Your message was from early this morning. Maybe you had showered before, so that the temperature first has to be reheated?
Is the thermometer working correctly? I have also had situations where I placed several next to each other and they showed different temperatures.

We have different settings on our heat pump than you do, and I still have to get into them, although the settings are currently working quite well.