I think the reason that dolphins disappear in Grian's video is that his dolphins are not name tagged. Dolphin can despawn like squid if no player is nearby, but when I name tagged them, they no longer despawn.
NeonBlaze101
I think the reason that dolphins disappear in Grian's video is that his dolphins are not name tagged. Dolphin can despawn like squid if no player is nearby, but when I name tagged them, they no longer despawn.