The gyms really need work. My boyfriend and I will go and defeat a gym together, and then either we have to add Pokémon in at the exact same time, or it will only allow one of us to. Also, Ive had several Pokémon come back after defending a gym for hours or even days and then not get any coins. Just today I had 4 come back and not a single coin from any, when I usually get 50 from each Pokémon. Fixes on gyms definitely need to be made.
Alinger99 about Pokémon GO, v1.37.2