[Ensorceled]

My Series 3 was dead on until this spring; there is a 5k run I do 2-3 times a week where the Strava would tell me I had hit 5km within a few meters of the same tree. Then it started misbehaving, usually 100-300m short of the tree, a couple of times 50-100m beyond the tree. The path in Strava was all over the place.

I tried rebooting, reinstalling the Strava app. Cleaned up some Watch apps. Didn't get better.

Finally I deleted all the watch apps except Strava: apple store, audible, three authenicator apps (why does Authy have a watch app?), my Bank's app (wtf?) etc. etc. etc. Turned off or configured for minimal sync anything I couldn't delete.

Things started tracking again.