Delta pidgeot bug help :D

So i was battling a trainer with magnezone at steam cave.I had my Delta pidgeot bite him to death when he paralyzed me with discharge spamming.Then for some weird reason the game thought my pidgeot reverted back to normal/flying type and magnezone’s next discharge was super effective on a dark/dragon type delta pidgeot…Any help or something else i should do to stop this from happening?