In survival, when entering the Nether Portal the "Building terrain" icon appears and nothing happens following this (I waited for 15 minutes to test this). I closed the game and restarted Minecraft and upon entering the world, it loaded into the Nether. I can then exit the Nether Portal without issue. However, if I re-enter the Nether Portal it freezes on the "Building terrain" icon again.

For reference I have copied the world, moved the Nether portal and tried re-installing the game, all of which had no effect on the issue.