Ok I downloaded and installed version 5.14 and it immediately sent an update and is continuing to send updates. I get an "Unknown Device" in the server log, but that's the next thing to work out. I saw in the github code that there were some changes to the location stuff between 5.14 and 5.15. I see that the option for "Location Accuracy" has gone away in 5.15. It appears something in those changes has broken the app for me and the OP.
For me, this is the only app were I have revealed this kind of problem for now... For the moment I stay with the version 5.14 up to find a real solution
This issue seems to be fixed with the version 5.17 :)
Is other people in the same case can confirm it ?
You can download any old version from GitHub.