Hi Ruvox!
Thanks for letting me know!
First of all, I have checked the anti-cheat logs and you aren't flagged as a cheater; the system seems to be correctly recognizing that you're experiencing GPS issues.
So the land capture block you've experienced is just a harmless precaution.
However, having analyzed a few dozen of trips similar to yours last week I have begun developing a new anti-cheat version that should be even more accurate and potentially allow to remove this precautionary block completely (as there's really a very clear difference between players like yourself and those using Fake GPS from my end; I am hopeful that at some point even the cheater punishment will become automated due to precision of this new system).
It will probably go live at some point around/after Easter!
As for the GPS position jumping to a previous location: we've actually switched to using Google Location Services API instead of just reading coordinates off your GPS, as Google's algorithms are a lot more advanced than anything I can possibly design myself (simply because they've spent more time developing their solution ) and many more devices are now showing accurate positions compared to previous versions.
However, I have honestly no idea how they work internally and cannot say why the API sometimes decides to throw you back into a last visited city!
It's quite possible that, as you noticed yourself, the accuracy level of your current coordinates is simply too low and the Location Services decided to use the last known accurate position instead.
* shrug *
Unfortunately, there's little I can do to improve the GPS accuracy further, as there are just too many devices working in different ways and whenever one of them gets really accurate some of the others stop working completely (as it happened in 1.17.5).
So we're probably going to keep the current version, but as mentioned above I will adjust the anti-cheat around it.