Incorrect resting energy Apple Watch 6

I recently upgraded from an Apple Watch 4 to a new 6 but since then the resting energy in Apple health (iPhone X) has been totally incorrect, I was previously around 1,800 each day and now it’s well below 1,000 most days often much less. Active energy & rings seems ok & when I check heart rate etc on the watch app that’s all what I would expect as well.

I have unpaired / repaired but it hasn’t made any difference. Any ideas?