Bucky doesn't seem to attack in 1-5 (he does move, but there haven't been any attacks from him at all) and 6th and 7th (including custom nights) he attacks once and just dissapears.
I don't expect the bugs to be fixed tho. It's bettter to prioritize current/future projects imo.
Edit: he might attack in 5th night as well, honestly I kinda forgot already.