Bug With Ender Dragon - Insta kill dragons breath

On our bedrock realm, we went to fight the Ender Dragon. We all had full protection 4 going into the fight. At the start of the fight, I was fighting an Enderman I had looked at , when the Ender dragon fired its magic at me. The Magic killed me instantly, and I had no time to react. I think this may be an issue, as with full protection 4 armor the dragons breath should not instantly kill you. This happened to all the Rest of my friends except for one. If this is a bug, I would hope it gets patched, and If not, I would reconsider the damage output of the Magic. This Happened to me the the Most recent update, 1.15 with the bees and honey.