Thanks for your help =)
I was not able to get MMM-PIR-Sensor running, even with your steps listed above. As it is deprecated I did what @karsten13 suggested and used another PIR (MMM-PIR). It had the same issue first, but using magicmirror-rebuild from https://forum.magicmirror.builders/topic/16074/electron-rebuild-and-magicmirror-v2-18-and-more?page=1 I was able to got the PIR working again.
So again: Thanks for trying to help and your suggestions!
@oliwer Hi. Is this the motion sensor doubling as a temp sensor? The temp sensor stuff they do not work very well and is very inaccurate. Could you run the following in your browser for me and post the results in an issue on my modules github page?
http://your_bridge_ip/api/your_key/sensors
