Homematic devices showing up as n/a after restart

[Merc3nary]

Hi all,
I have installed Raspberrymatic and have successfully added 5 TRVs.
They are visible and accessible on my Lovelace dashboard where I can control there setpoint temperature, see the current temperature or select programs.
However after each restart they are unavailable in Lovelace, showing N/A everywhere.

Only after I go to Raspberrymatic and select one of them and for example change the temperature they become available in Lovelace as well. Sometimes they also seem to loose the connection when switching from manual to auto mode. But this does not happen every time.

Does this have to do with the V_last_reboot script and automation? I have followed the instructions (even the latest update where homematic was replaced with raspberrymatic in the template) but either this has got nothing to do with the solution or something is not working.
Also the sensor which should show the time and date of the last reboot always shows 01.01.1970 00:00. Is this the way it should be?

I love the integration but would like to fix this. Would very much appreciate your help.

Thanks and regards,

Merc