I’ve searched but unable to find an answer to this question anywhere.
Is there a limit on how far back CityStrides will sync with Strava? I have used Strava since 2013, but I only see data in CityStrides to beginning of 2019. I know there is a lot of places I’ve run that are not showing up.
Is there a way to import or show this past data as well?
Nope, no limit. It seems like there’s some edge case somewhere that causes a sync to just stop. 
I haven’t been able to pin down the exact issue yet, but syncing again will fix it up (I just started another sync for your account).
Brilliant! Looks like it is all appearing now! Thank you!
Yes I have some old runs that have not synced- here’s one from 5/29/17: https://www.strava.com/activities/1011279180