First of all, sorry if it has been asked already. I couldn't find anything similar, though.
I tried to attack a hostile gym and it worked fine until then. I also caught some Pokémon on my way there and collected a few Pokéstops. So my guess is, that the connection was fine.
Also the GPS positioning was good and I didn't get pushed out of the gym's range.
(The gym itself was at a main station, so it's a pretty busy place.)
The issue itself:
I could select the gym, tap on fight and select my combat Pokémon and start the fight with no issues. But as soon as the countdown for the first fight ended I got thrown back to the main menu of that gym and I had to tap on the fight button again.
I haven't seen this before and it was only this one gym. There was another gym in the area, which I could use as intended (this was a friendly one, though).
Do I have to report that gym or was it just a temporary problem? If so, what kind of problem was it?
Update:
I have collected several details about this using the classic method try and error. So far I got it reproduced even without any connection issues.
Narrowed down it can be caused by:
- GPS Problem (not server related)
- interrupted previous fight (app crash, etc)
- server issues
Best Answer
Were you at a location where GPS accuracy may have been "suboptimal"? What I experienced often in those cases, is that your location bounces around the area when your GPS updates and decides that you are now in a different location. If this temporary new "wrong" location is too far away from the gym, it may cancel ongoing fights.
In this case, you may sometimes still see the "Gym too far away" message in the gym main menu for a short moment.