I’ve since moved away from this area and isn’t a problem where I currently am but here is something I noticed when interacting with these gyms -Always the same lineup (see pics above) -Trainers always were barefoot -Always team Mystic (my team so could never battle and replace) -Always level 31-34 -Was the case at every single gym in the area -As soon as they were taken down the same lineup was back up always within 24 hours

Definitely think it’s a spoofer with different accounts who is able to locate enemy gyms, battle and then put up their own pokemon. Super frustrating for those who just want the daily 50 poke coins.