Two bugs in the Chamber of Memories in the helix chamber:
1) Beating the Goomy guy sends you to a water tile in the Coral Ward on foot. You can't surf or do anything from there, you're softlocked.
2) When you pick a partner to face the guy on the left, it spawns a seemingly random party member, not the one you actually picked. For example picking Aya spawns Florinia and so on. Aya is spawned by more than one option and none of the options spawn Julia (who's the one I actually wanted). Amaria spawns herself but only has 2 pokemon. Picking Titania straight up crashes the game.
And in the Commander fight in the CoM:
1) Using Earthquake turn 1 as the last pokemon to move errors out and the move does nothing. Same thing happens occasionally when the Venusaur uses Sludge Bomb at any point during the fight.