Charge 3 distance information inaccurate

[Ash2107]

This was working fine until a few weeks ago. Now when I start a run from the watch itself the distance logged is completely wrong, which throws off pace etc. Starting the same run through the app rather than the watch gives an accurate read but the same run shows consistently as 1 - 2 kilometres shorter on the watch logged run compared to directly through the app even though the map generated for both runs is identical. How can I fix this? I've tried manually adjusting my stride length but makes no difference. I find having distance and pace on the watch during a run really useful but now it's basically not usable 

Moderator Edit: Clarified subject

[AlejandraFitbit]

Welcome to the Forums, @Ash2107.

Thanks for troubleshooting this distance issue. Fitbit devices calculate distance based on the device’s accelerometer data and stride length setting.

Default stride length is based on your height and gender. If available, Fitbit devices use GPS data to calculate more precise distances.When you sync your device, our algorithm interprets the data from the device, and you see your distance traveled in the Fitbit app. 

Note that when you track an exercise with GPS, both GPS and accelerometer data are used to calculate the distance shown in the Fitbit app. For more information about accuracy, check the article: How accurate are Fitbit devices?.

Let me know the outcome.