I think this started happening in the new update: my Edge 1000 won't reach 100% battery charge.
I have seen this was an issue with the Edge 1030 last year: https://forums.garmin.com/sports-fitness/cycling/f/edge-1030/166138/only-charging-to-97
Seems like it could be software related. If that's the case I would assume other folks would also be seeing this?