When taming, make sure not to trap it. When it comes in contact with a barrier of any kind, sabertooth salmon are spawned in behind it. The salmon will bite it an reset its taming. If you tame it in the open water with no barriers it will tame pretty easy. You can not put berries into your hot bar and passive it or honey. You can not knock it out to tame either.
They have patched the render range range so ignore any tips that say to leave render as it will no longer. Guess I’m stuck with the turtles I have, I’ve spent three hours trying to take one of these things and had it walk out of the water which reset it taming! It was at 80% that time. Never got it above 20 after that. What he for the saber tooth salmon that spawn to kill the swarm if they bite the turtle it resets to zero and you start over. Extremely frustrating way to tame a creature. I would like to beat whoever came up with this idea.