Got a 7 months old Prusa MK3s+ connected to octoprint. And its been working like a charm.
I´ve been away and havnt touched the printer or octoprint in like 1,5months. Today i started everything. After booting Octoprint i was told a new version of octoprint was released and i updated.
Started a print and my prints is all over the place until i got emergency stop.
Hmm, checked Printers firmware and Octoprint, both are on the latest.
After a hour i try another print and the temps is all over the place agian.
That looks a lot like a hardware issue with the printer's thermistor - it it basically physically impossible for it to change temperature that fast. I would double check all the wiring and possibly reach out to Prusa support for help with working out what might be wrong with it.
When you tested setting the temperature without OctoPrint, were you able to start a print? I wondered whether it started to have a bad connection/reading once the printer began moving to start the print, as the temps whilst it is warming up look OK.