Trainers, there is a glitch that causes Pokemon to appear incorrectly in the Gym, as well as showing incorrect defender timing. This glitch/bug has appeared all over the globe and causes major problems.
Gyms are currently bugged and they display wrong Team color and show that your Pokemon have been there for a very long period (up to 18,500 days.
So how to fix it?
Apparently, all you have to do is click on those Pokemon and they will refresh and show the correct time.
Niantic is aware of this glitch and they’ll try to fix it ASAP.
Trainers, we’re looking into the recently reported odd behavior in Gyms, e.g. Pokémon appearing incorrectly, incorrect defender timing, etc.). We apologize for the inconvenience.
— Niantic Support (@NianticHelp) June 16, 2020
Do you have the same problem?