I tried 2 garmin fr45s, issue, fast too many steps, about +3 times more than real (real by manually count or old farming watch). I returned them both.
Now I bought a more expensive fr245, and the daily step count is way to high too.
Reseted, last FW, etc...
I see, a lot of posts with this issue, zero solutions.
I contacted Garmin s SAT, all they can offer is a "possible" giroscope repair on a new watch. Low chance of success repairing, makes it not worth trying.