I had gone into the end with a friend who had joined the world with me, I was using an enchanted bow that had Flame I, Unbreaking III, Punch II, Infinity I, and Power V. The Ender Dragon took one hit from it, and after shooting maybe 50 arrows into it never got damaged again. Ultimately, we killed the dragon with swords then I reloaded my world, and respawned the Dragon with the crystals. Again, the same issue.

Another issue that I noticed is with the Dragon Breath attack and when the dragon shoots a fireball at the player, the area of effect seems to be larger than it used to be and I'm unsure if this is a change that was made recently or if it's another bug. The area seems to be around a 4x4x4 block area and pushes the player up into the air while dealing constant damage.