I’ve tried that, the two are no longer connected but it still shows calories remaining (which 2000+ as it’s now not getting the feed from MFP with the calories consumed) instead of total calories burnt. I don’t know how to get the calorie count back.
I just tried this and it did revert to resting and active after I synced.
I went to the 3 dots (more) on my iPhone, then Settings, then partner apps and disconnected MyFitnessPal that way.
After that I synced and now am showing the original resting and active calories.