hello people,

so something weird is happening i was printing PETG with the heated bed set to 87G
but once every 10 seconds the printer says that it's 60G and then jumps back
anyone an idea? i have uploaded a foto of Octopi

I'd say that the spikes are too short in duration to be a true representation of the actual bed temperature, so it looks like a noisy signal. Could be a bad connection or picking up interference from a stepper or it's wiring. Whatever the cause, it looks like a wiring issue to me.

Yes, looks like a bad wire. I had a similar issue with my extruder, and I found out that one of the cables was almost broken, giving a bad connection during extruder acceleration.