Please report your sync issues here: Individual missing activities, missing backlog (no activities prior to a certain date), etc…
I’m going to use this single thread as a place for you to report any sync issues. I’ll move the post over to Archived Synchronization Issues after I start a sync for your account. That thread will act as a catch-all of all the sync issues we’ve ever had to work through.
I may not reply to your note here - I may start a sync for your account and move your note over to the archive thread. Let me know if you’re re-reporting an issue so I can pay closer attention to it. 
Strava users: CityStrides recently exceeded their API rate limit, and there are a lot of missing activities as a result. I’m handling the backlog manually, so that I stay below their limits. This is going to take some time. Please hold your sync issue reporting until October - I think I’ll be caught up by then.
Supporters: I have temporarily disabled the “sync now” feature. I need to slowly work through the backlog of missing activities at a manageable pace. Sorry for the trouble.
EVERYONE: Do not de-authorize/revoke CityStrides from having access to your activity tracking service. Doing so deletes all of your data here. Only de-authorize/revoke if you want to leave CityStrides.
Activities with missing maps: Delete the Activity (while viewing it, there should be a Delete Activity [ID] entry in the menu) and the next sync should bring it back in correctly. If you have too many of these, let me know - I’ve got a script that’ll do the whole process in seconds.
there are important details in there & I keep it updated.
Read his initial post for details.