"Gym repeatedly returning to grey."

#PokemonGO: Be kind. I normally just lurk. I’m level 35 and an older player. I’m not technically minded and my kids laugh as I’m not up to speed with the intricacies and stats for detailed playing. I just love the game and have played since it was launched.My question is about a constantly grey gym. I’m in a city so lots of gyms and pokestops in the immediate area. The gym is a gold level for me (I’m team Instinct). It’s a statue in the exact centre of a grass only park and I can clearly see it from my apartment. There are absolutely no other structures in the park to obscure my view.For the last three days the gym is constantly grey. All other gyms in the area are normal. If I put a Pokemon on the gym within 10 mins it goes grey again. And no one has been near enough to battle it (as I said, I can clearly see it from my apartment). I’ve put a Pokemon on this morning and before I’d left the park it was back to grey (no one else there).It’s not just for happening for me though. Twenty mins ago I watched the gym become Mystic and the trainer started to walk out of the park. The gym changed instantly back to grey. I could clearly see the guy looking about him as there was no one else in park besides him.Could it be related to the fact that this gym was the location for an ex-raid last month?I can’t find anything on here that seems similar to this to explain what is happening. via /r/pokemongo http://ift.tt/2F0ESWO