Feeding a dolphin causes a crash when structure generation is turned off

I was playing on a custom 1.14 map created by myself, when I found a dolphin swimming in the ocean. Since I had turned naturally generated structures off, I was curious as to what would happen if I fed the dolphin. When I fed it some fish (raw cod), the game froze, and I could not exit my world. After waiting several minutes to see if anything would happen, I forcibly closed the game via the Task Manager. 

I tried this three times with my custom world, which yielded the same results. I thought maybe it was due to a corrupted world file, so I generated a new, 1.14 map, with structures toggled off. The same thing occurred when feeding a dolphin in this world.