Ender Dragon Disappears While Fighting It

I respawned the ender dragon for the fourth(edit: fifth) time (I believe) on my Bedrock world that I had transferred originally from the PlayStation 4 Edition (the 4J version, NOT the new bedrock edition) over to my pc. While I was fighting it, I was in roughly the middle of the center island when the dragon suddenly vanished and its health bar disappeared. Every trace of it was gone. When I died and went back to the end, the dragon was still not there. Luckily, I had made a copy of my world previously. Otherwise, I would have been softlocked in the end, as the portal back to the overworld was still unactivated from the fight.