When an activity is resumed (e.g. after a bluetooth disruption requiring a zwift restart), only the activity from before the resume is saved in the .fit-file. The activity after the resume will not get a new .fit-file for both parts of the activity but instead only get the partial activity before the resume.
My activity feed shows this:
before bluetooth disconnect: activity 1088455942434996224
after bluetooth disconnect: activity 1088447533862092800
The .fit for both activities is the same, the one from before the disconnect (8km instead of 58).
After some more investigation, I saw that there are two .fit-files on my android device for this activity, one from before the resume and one after:
2022-05-27-16-27-56.fit
2022-05-27-16-44-09.fit
The .fit -file after resume seems to be invalid (size is only 584 bytes), the ride data wasn’t saved in the .fit-data for some reason.
Had the same and opened a case as clearly a bug. Let’s see if they fix it at some stage. My setup was IOS & bluetooth. Both fit files contained the same information despite Zwift showing the correct overall time and distances for two activities (pre and post resume).