Zwift Power fit file analysis issue

There seems to be the a bug with the parsing of the zwift uploaded fit file for a recent even of mine. It analyzed my 20min power being below what even my average power was. This also resulted in a normalized power below my average power and a variability index of -7%, which shouldn’t be possible.

Event ID: 4278662
Rider: Kenny Polonski (COALITION)

Looking at the same uploaded data through, the data appears to be analyzed properly and I get a 20-min power of 287w or 3.39 w/kg. Before the fit file was uploaded (green lightning bolt), those were the numbers that I saw.

Screenshot 2024-03-21 073518

I also uploaded the fit file manually for analysis and the same issue is present on ZP
Analysis set ID: 415441


Welcome to Forums @KPo. This is Juan from Zwift. A big thank for sharing your concern here. I comprehend how surprising it is for you to see that your fit file data is not accurate what the one you saw in first instance.

Compared the same fit file from different platforms was a well-thought-out idea to find out the discrepancy. Well done! We are currently investigating issues related to processing fit files and power values that are inaccurate.

Thank you very much for pointing this out. Once we have updates on this, we will share them with you.