FW 21.16 : Stamina is now always <1%

Update: It bumped up from 1% a little yesterday, and insisted that I had less than 1km left in the tank... then I biked 50km. So frustrating that this feature seemingly broke.

Final update: This seems to have resolved itself over the last few days. I have paired the HRM Pro Plus heart rate monitor, instead of my usual arm band sensor, so I'm not sure if that did it or not, but the values are back to what I see as normal.

I have to open this topic again, and the stamina feature is still stuck at 1% for the majority of rides. Once in a while, it does seem to be back at 100%, but it's usually not. It seems to work more often with a third-party HRM, and less so with the Garmin HRM Pro Plus, which is odd.

Any suggestions on getting this working on a more consistent basis would be appreciated.