Getting kicked out of raids?
This has happened twice recently where I get in lobby for a raid and walk away from the gym and by the time the raid starts, I instantly get kicked out. The first time, I was in a car so maybe there was a distance threshold? But the second time I could still see the gym on my map, which was what I thought was necessary for continuing the raid even after you were out of range of the gym.
Answers
I remember reading that you need to remain within 80 meters of the gym if you're still in the lobby and want to avoid getting booted out. Once the battle starts, then you're free and clear to move away from the gym if needed. Still, be careful about this. If the game crashes or anything goes wrong, you'd need to return to click on the gym to re-engage the catch sequence on the raid boss.
*cough* in addition to the 80m radius, there's also a trick to make drive by raiding easier.
Get into the lobby, and while still in range, turn GPS off. While in the raid, once the timer appears, reactivate it. Note that if you get knocked out, you will not be able to rejoin.
Similarly, you can go as far as you like once the timer appears, but you'll have to stay in the lobby if you get knocked out.
In either case, you'll still get the chance to catch.