Distance inaccuracy with connected GPS on Fitbit app

[gonecamping]

I've been using the Fitbit app on my Android phone(s) to track walks and runs for years. It has always been the most accurate tracker compared to others I've tried in the past. 

However, since the end of April 2021 (29 or 30 of April I believe) the distance the app shows is significantly higher than what it was before. 

For example, a walk I've tracked tens of times in the past between 2.16 - 2.18 miles, will now show 2.9 miles.

Taking a closer look at the map in the app, I noticed that there are many small backtracks, even though I never backtrack on my walks. Here is an example: 

Looking back on maps of walks before the end of April, there are no backtracks like these.

I exported the .TCX file of one of the walks and I used a GPS map editor to delete all the backtracking points. The total distance of the walk after that had dropped to inside the range of the correct distance.

For further testing I tracked a couple of (the same) walks with both Fitbit and MapMyFitness. The distance measured by MapMyFitness was very close to the correct distance, but that of the Fitbit app was 10-20% higher. I analyzed the .TCX files from both apps and while Fitbit had many backtracks (like the map above), MapMyFitness had none.  

More details:

• Phone: Google Pixel 4a 5g running Android 11, with Fitbit app v3.41.2 installed
• Fitbit device: Flex 2
• Fitbit app on phone has Location Access permission set to "Allow all the time",
  and Battery Optimization to "Not Optimized" (no restrictions)
• My walks are in residential areas with no heavy foliage or big buildings around. Also, I have tried having the phone in my hand and in an outside pocket and it maintains a strong GPS signal,
• I don't start the walk/tracking until a GPS connection has been established. 
• I'm not 100% sure about this, but it seems like since around the same time this issue occurred, the app will countdown 20 or so seconds when I press start to start tracking the exercise

Was there an app or algorithmic update around the end of April that could have affected the app's GPS/compass sensitivity or how any inconsistent points (those going backward) are included in the app?

Is there anything else I can do to improve the accuracy of the distance of each exercise? 

[MakMak]

Hi, @gonecamping! I'm sorry, I don't have an answer for this, but I'm really interested to hear if you do get a response. One question I have for you is whether you have tried to troubleshoot by using another app to track GPS - would indicate whether it might be a systemic issue with your phone or just unique to the Fitbit app.

I just went into my app to look at GPS. I have been using the on-board Sense GPS to track my hikes lately. I didn't see this same behavior.

[gonecamping]

Hi @MakMak, thanks for taking the time to check your app and reply! 

Yes, for the past 10 days I've been using both the Fitbit app and MapMyFitness to track my daily walks. Every time Fitbit has backtracks while MapMyFitness doesn't.

I downloaded and analyzed the .tcx files, which give a long list of trackpoints (with coordinates and timestamp) during the exercise, from both apps. MapMyFitness takes more trackpoints (2561 vs 1626 for a 40-minute walk) and had no backtracks. Fitbit has many. Here is an example screenshot of the two tracks zoomed in: 

[Giampi71]

Hello @gonecamping ,

I've just test it (I use Pixel 4 with Android 12 beta and Fitbit app version 3.41.2) and I don't have this problem. See screenshot

Actually I'm not sure how to help you out and your system is very similar to mine.

[gonecamping]

Thank you for the feedback @Giampi71.

You are right, our systems are very similar and the track on your map looks good. That's what my maps looked like up until the 28 or 29 of April.

I didn't make any changes to my phone or the Fitbit app before the problem started, that's why I'm wondering if it was an update Fitbit made. Perhaps my account is part of a change Fitbit is testing? I don't know what else to think.

[gonecamping]

This remains problem for me. 

I tried downgrading the app to previous versions. I couldn't find previous app files to download, so I installed them through Aptoide. 

I tested versions 3.40.1, 3.39, and 3.36.1 (among others), they all log backtracks and inflate the distance just like the current version from the Play store. 

Here's what's interesting. I found and installed a Chinese version of 3.36.2. I assume it's Chinese because the map used is Baidu instead of the regular Map. This version is very clunky (the map is slow to react to touch, some force closes etc) but the tracking doesn't have the backtracks. The route is smooth like it was before this whole thing started.  

It's so bizarre! Can anyone help?

Thanks

[BenLaplante]

Similar to what I expereince. I have a Versa 2. For example this morning I went for a bike ride and chose biking on the activity menu. I start my ride when the watch is connected with the phone. I also have a Garmin device that I use. I did 42 km as per my Garmin device but my watch shows 0.89 km. All the indicators of my ride are showing but not the distance.  I never had any issues with the watch before. I did  all the recomended steps without success.

My phone is a LG X Power 3. The connexion issue strated recently. Thank you