I have similar issues on my Race S several months ago an apparently fixed a couple of firmware update ago. In recent weeks I realized the problems popped up intermittently. I had been diligently sync-ing and exporting Stryd-only data for my runs and compare them to Suunto’s data. About half the time, the power numbers matched well, while the others will be off by 5 to 10w. And when the data got merged into Power Center, the Suunto’s numbers persisted, “compromising” the overall data quality. This is really frustrating.