Disclaimer: I am not a GPS expert.

I had been using RWGPS with an Android phone for tracking my rides. After three or so years it just started to lose tracking randomly - like I'd have a straight line going over a bay or between places where there are no roads. I contacted RWGPS support (who were very helpful) and started troubleshooting. At first they had me download a "GPS Test" app which will test your phone's recognition of satellites - both in number and strength. So maybe give that a try.

Ultimately, the problem ended up being my phone: RWGPS' software would not play nicely with the older Android OS I had, which from memory was maybe 3 versions behind. I got a new phone and have had no problems since.

YMMV. Good luck.