I saw in discord that the new update made it so you could use pokemon even if they were in the gym. My raichu was in the gym and I can send him out to start a battle. But if I try to switch out another pokemon with him it will just tell me he is in gym.
Here is a screen shot of me trying to switch to raichu, but it does not let me and says in chat Raichu is in a gym
Hey zzalen, are you initiating the battle with the Raichu or are you switching in the middle of a battle? You currently cannot switch then, and can only initiate battles with pokemons in gyms. This is a known issue and will be fixed in the next update.