Since upgrading to 1.14.1 from console edition turtles will no longer dig in the sand when being bred.  I get an exp orb and one gets fatter but it never digs.  I have tracked a preggo turtle for 2 game day/night cycles and it just swam around in the ocean and never went to a beach to lay eggs. 

I also started a new creative world and spawned upwards of 50 turtles in a desert/warm water biome and bred them on their spawn beach.  Waited about 2 game days and flew over the area and didn't see any turtles start digging.

I switched back to console edition and started a new creative world.  Spawned a couple of turtles and bred them, immediately one started digging and laid eggs.