Unfortunately, not having a great experience again, I thought it was solved with @mcneese.chad solution.
You can see below that it is fluctuating but the peaks give the impression it is stable. However, it seems to get worse as a function of time. The cool down at the end was pretty bad tbh. Also, during the long segments, it is making it fluctuate ±30 watts, this is incredibly knackering! (like another totally different workout.)
FYI: other apps uninstalled, my garmin head unit is however connected to my gear too, but it should not control anything. Any ideas? Urgent help needed! : (
(@Nate will also write to support.)
Zoom in off the cool down: