The reason for that would be GPS drift because of bad reception on your phone. You could pause the recording while sitting on the bench or setup autopause to prevent that.

Autopause doesn’t work well in Strava.  And anyways, I should not have to do manual pause.  When I have done this in the past, I have sometimes forgotten to unpause and lost the remainder of the activity.

In this case, I was in a wide open area with a clear view of the sky.  My phone had more than enough battery power.  If the satellites were causing this issue, then Strava should put out a message saying so.

If Strava is having problems determining whether I am moving or not, then it stands to reason that they are also likely having problems calculating accurate data WHEN I AM MOVING, thus making Strava statistics unreliable.

I really was not familiar with GPS Drift (and frankly, as a user, I should not have to be familiar with it).  Dealing with it is a developer problem, not a user problem.  It’s what they get paid the big bucks for.

Here’s a company that offers solutions that Strava may want to avail themselves of if GPS Drift is a big problem for them:

Understanding GPS drifting: Challenges and solutions
Marc Kranendonk | Content Manager
October 6, 2023
https://www.roam.ai/blog/understanding-gps-drifting-challenges-and-solutions

I don’t know what you expect here from the app. If it detects that your location changes because your phone said so it will record that. How will it know that you are sitting on the bench instead? And Strava could only notify you if it doesn’t have GPS reception anymore. Maybe you would be better served by using a sports watch for recording, at least the newer ones have usually better reception than phones and are more convenient during running anyway.

And maybe the GPS troubleshooting articles can help:

https://support.strava.com/hc/en-us/articles/216918967-Troubleshooting-Android-GPS-Issues

or

​@Jo61jo  do yourself a favour and get a device with proper GPS. 

You seem to be referring to “technical background” - well, then you're surely familiar with the GIGO principle. The Strava app simply processes the data that your device produces... 

And, by the way the replies from ​@Jan_Mantau are giving the information that you need to resolve this issue. If you wanted help, you got it. If you only wanted to complain… sorry, we can't do anything for you here. ‍♀️

You have not looked at the GPS data, so how exactly can you state “bad GPS data”?

Hey Everyone,

Thank you for your ongoing participations in this space.

A quick reminder that the Community Hub is intended as a space for peer-to-peer support. 
Our contributors, including our Superusers, generously share their time and knowledge to help troubleshoot and guide fellow community members in this peer-driven space.

While we understand that technical issues can be frustrating, we ask that all conversations remain respectful and constructive. This ensures the Hub remains a welcoming and productive environment for everyone. Strava staff monitors discussions to help ensure community guidelines are being followed and to flag any pervasive or known issues internally. Let’s keep the conversation focused on sharing helpful insights and supporting one another. Thanks again to everyone contributing here.

Moving on, I re-did this activity to test for the problem occuring again.  And it did so in the exact same spot, where I gained .02 miles simply sitting on the bench over 13 minutes!

Not knowing what else to do, I have some GSP utilities on the phone and tried opening them and taking some screen shots.  If there was anything I should have been looking for, I did not know what it was. What to do with such utilities might have been a helpful counsel from the volunteer help here.

There looked to be plenty of satellites available, so I still don’t understand why Strava could not maintain and compensate as necessary for any so-called GPS drift.

I subsequently made two further stops along the course to check if the same problem was evident.  At one of them, I had a solid zero in speed while sitting on a bench.  At the other one, I had some minor drifting.