A similar issue has been reported at

https://www.reddit.com/r/Strava/comments/k8n1t9

Hi @jdujic 

To troubleshoot this situation, please try turning your phone completely off and then on as well as turning your location services off and then on again. Location services are located in settings > privacy > location services (turn off/on).

Also, sometimes GPS data quality can be improved by simply giving your phone more time to acquire satellites prior to starting your activity.

For more tips on how to improve your GPS quality see our article on Troubleshooting GPS issues for iPhone

If you find that the information above does not resolve the issue, please perform a GPS reset on your device:

GPS reset instructions:

1. Close all open apps on your phone.
2. Then go into settings and turn on airplane mode.
3. Next, go to settings > general > reset and choose reset network settings (you will need to re-enter your wifi passwords!)
4. Once your phone has reset, go to settings > location services. Turn this setting off and then on again.
5. Finally, go to settings > privacy > location services > system services and turn setting time zone OFF.

If you continue to experience the same trouble after performing a GPS reset, please let us know.

Hi @Jane11

It took a while to test it, but no, it did not solve the problem. I believe the problem is not in GPS as such, but in the algorithm how a gpx track is recorded and noise analyzed. Noise is immanent to GPS recording, but my particular GPS sensor seems to be more noise-prone, and it simply shows up in the traces.

There is, however, a well-known "noise cancelation" algorithm for GPS tracks known as Kalman filter. An excellent explanation and implementation can be found e.g. here. However, it seems that it is not implemented on Strava side either, and it should, at least as an option to post-process the data.

I've just tested Strava's "Correct distance" option on my recent hike, reported as 15.69 km by my iPhone (the correct distance is some 15.10 km, as previously measured by two separate smartphones), and it made a mess out of it, "correcting" it to 16.98 km. It seems something is seriously wrong there. A properly implemented Kalman filter can only shorten the reported distance, as it filters out all the wobbling, yet I've only seen the option increasing the total distance.

As a workaround for my problem, I ordered a Garmin watch as a present for my upcoming birthday. 😉 😉 And I carry my old phone to my runs (hiking distance is of lesser concern).

Hi @jdujic

Thanks for getting back to us. Our Support Team would be happy to work with you to investigate this further.

Please submit a support ticket and somebody will be in touch.

I have the same problem. Any solution recommended? Or should i open an support ticket as well?

I have the same Problem!

my old iPhone SE 2 World better than my new iPhone 13 mini. Can you please help me

For the record, I haven't raised a support ticket -- I purchased a Garmin smart watch instead which has outstanding accuracy. Too bad that Apple blew it with those bad GPS units.

it seems that the GPS reset instructions worked for me (tried it one time after the reset).

looks not perfect but way better than before

did you fix it already?

Hi Patrick, no its not fixed. For biking records look fine, but the forrest running records look still strange. I will try the reset GPS tomorrow, but i already think about to buy a Garmin watch as well 😞

Do you think it's because of the speed? 
I can't understand why the problem can't be fixed 😞

It seems speed has an effect on the recording. But not sure.

Same problem here, also iPhone 13 mini