A grounded Poison-type pokémon removes Toxic Spikes switching in.
A Air Balloon Poison-type pokémon doesn't remove Toxic Spikes switching in (without Gravity).
But what happens if the pokémon is in play and the balloon gets broken? Are TSpikes removed or does the pokémon need to be switched back and forth?
(I can't test it in game, it happened on PS and I don't want to report a false bug)