One instance of broken AI is with how the Ender Dragon descends to the fountain. The Ender Dragon is supposed to dive down to the fountain, but in versions after 19w08b, the Ender Dragon instead flops back and forth slowly descending in an obviously buggy manner. The Ender Dragon also seems to very rarely descend to the fountain unless all of the crystals are broken, something that it did more often in versions before 19w08b.

Another instance of this broken AI is with how the Ender Dragon phases are broken. When the dragon is supposed to be circling the arena it instead will do that same buggy flopping back and forth motion it does when descending to the fountain, or it will simply fly in a circle/triangle over and over. It will do this between two places over and over until it decides to either fire a dragon fireball, charge a player, or it decides to descend to the fountain. This part of the broken AI can be seen best when comparing the after 19w08b AI to the before 19w08b AI directly side by side, especially since in versions before 19w08b the Ender Dragon flies up and down smoothly and fluently when circling the arena, while in after 19w08b the Ender Dragon tends to just stay on the same y-value when circling the arena. It also just seems to fly faster and more fluently in general in versions before 19w08b.