I think I posted about this on the Reddit page Anyways, allow me to get on with this bug
I have found that, when in Anastasia's Gym, whenever you defeat the Gym Leader's Klefki, the game always seems to crash. It gives me the same feedback every time, no matter what Pokemon I use.
I don't know if this has been stated before, but it is a major issue, as the game cannot continue without defeating the Gym Leader, obviously.
Thank you for taking the time to read this, and I hope that this bug can be fixed in the near future.