Wrong activity date
We are aware that some activities are saved with the date 2003.
We have looked into the issue some more and we found that this is mainly happening on Samsung phones. You can check it out by installing the GPSTest app from Google Play.
This tests your GPS, and if the time turns red you can tap on it and it will explain the GPS problem.
This issue is related to a software update on the phone and therefore, we won't be able to resolve this issue from our side. We recommend updating your phone's software when updates are available.