Strava is syncing to fitbit app but not vice versa

[lomagna]

I have a new Charge 5 and I'm using GPS-tracking to track my runs on there. Sometimes the GPS fails so I still also track my runs using Strava with the intention that I will just delete one from my strava app. The strange result that I'm finding, however, is that the strava runs sync to my fitbit app and I have to delete one from there, but the fitbit runs are not syncing to my strava app. Any reason why they would only be going this direction? Aren't the fitbit runs supposed to show in my strava app when they are connected?

[t.parker]

@lomagna I'm surprised the runs recorded with Strava sync back into the Fitbit account. That never worked for me. I have a theory of why your setup may not work properly. Basically, when you sync to Strava activities overlapping activities sometimes one of them will be refused. I experience that in my setup where both the Zwift app and Garmin are linked to Strava. I want activity tracked by Garmin to obtain Training Effect metrics but in Strava I want to have Zwift workouts only so I assumed I would need to delete the session sent from the Garmin account. And here's an interesting thing. If I finish and sync Zwift first then Garmin activity will never sync to Strava. If you use Strava to record then I believe Fitbit is being refused from sending your run because of an overlapping time frame. My case is slightly different (I don't record using Strava, my data sources are independent) but behaviour seems to be very similar. Hence my theory - Strava may refuse syncing activity that overlaps with another one.