Raspberrymatic integration -> Exception: could not convert string to float: ''

can someone please help.
In my home-assistant logs I can see below warning every 30 flooding my logs.

[pyhomematic._hm] ServerThread.getAllSystemVariables: Exception: could not convert string to float: ''

I did check for my variables, but except for the V_Last_Reboot all variable are out of the box.
V_Last_Reboot has been created as string according to the documentation.
Below are the screenshots of my raspberrymatic.
How can I identify which variable is causing the problem? And how to fix this.

As it is trying to convert to a float it must be one of the varialbes with the number-type. So either Alarm messages, _ DutyCycle_ or Service messages. Check the values of those.

I never used those variables in my raspberrymatic. I just performed the basic configuration introducing the V_Last_Reboot according to the documentation.
However after my update of home-assistant to the latest version today, the message is gone.