Hi Bastian, first - welcome!
You can try to use the last FW for J1 - v2.8.0. It is the first implementation of Octoprint compatible server into J1 and has several issues, but it works. Here is the link for download: Snapmaker J1/J1s Firmware Updates and Downloads .
The discussion about this version is here: Firmware beta for J1/J1S! 2025-12-31 . Please note: evene the dates of FW v2.8.0 are different, the binaries are identical.
Anyway, I am almost sure that the head colisions are caused by prepared gcode. What slicer and profiles do you use?