PI4b crashs using air condition remote?

OH2.5 Pi4b SSD attached and the Aeotec ZWAVE dongle.

I would like to share a really crazy PI4 behaviour. Maybe someone can explain and help how to avoid this?

I do have a DIMSTAL air condition split device installed next to my PI4b (approx. 50 cm).
Suddenly I figured out that the AC remote wasn´t working anymore, so I used ALEXA for the AC control. Playing with the remote I noticed that OH wasn´t working anymore, again PI crashed, no reaction.
Hmmm so I replugged power and meanwhile the romote of the AC was working again…
I changed some values of the AC with the remote and finally switched it OFF.
… and OH&PI was crashed again. What is this strange behaviour? Can the AC remote or the AC itself crash the PI?