I have been checking in a lot of forums that talk about teddiursa and no one seems to know where he is hiding, and I have checked really hard in the game and haven't find him more than twice so yeah I think its bugged
I used a Gardevoir and a crobat, another that may help you is an alakazam because his psychic will probably knock out almost all of aya pokemon with one hit
I have a silly question, how can I change the weather on my game, I have changed the day like 40 different times and all I got was clear days or windy days