Can’t adjust mileage in the iOS app

[SunsetRunner]

Went on a hike this morning and my watch’s recorded distance was off by 1.8 miles (not the first time this has happened). It recorded it as 6.8 miles but the correct distance was 8.5. 

I can change it in the app but as soon as I click “Done” it reverts back to 6.8. 

Why won’t it accept the manual change? I know I can delete it and add it back in but then I lose all the other recorded data (heart rate zones, etc)

Moderator edit: subject for clarity 

[LiliyaFitbit]

Welcome to the Fitbit Community, @SunsetRunner.

I appreciate your participation in the Forums and sharing that you can't adjust the mileage in app for your hike activity. Thank you for providing the additional details, I understand your concern and I am glad to assist you. If you can't edit the distance from your recorded activity, you can delete that activity and manually enter it with the desired information. For more information, see this help article. I understand that this is not convenient and appreciate your feedback. Our team is always working on improving our devices and user experiences, and your comments are always welcome. Feel free to post your idea in our Feature Suggestions board. That way other users can comment and vote on the idea to show their support. You can read the FAQ to better understand how that board works.

GPS accuracy depends on the signal strength among other factors. A weak GPS signal might affect the accuracy of your route and other activity data. For more information, see How accurate is my GPS data captured by my Fitbit device?

I also recommend checking out this article with the information about the different factors that can affect the GPS: How do I use GPS on my Fitbit device?

Additionally, I recommend checking if your Fitbit app is updated to the latest version as updates come with new features and bug fixes: How do I update the Fitbit app?

Let me know how it goes. I'll be around if you have any additional questions.