I am unsure what is causing this issue for you, I have tested many times in both the devkit and in-game I cannot repeat the same issue.

Try use commands "walk" then "fly", then again "walk" while mounted. This is a bug of the game itself, which sometimes thinks that you have noclip enabled.

The walk, fly, then walk again while mounted (then dismounting) does not work that well. It works every once and a while but then it stops working. Any other ways to fix it or am I going to have to remove this mod until this is fixed? It seems to do it every time I mount or dismount a tame no matter what the creature is. I am in singleplayer, so I am not sure if this is because of that somehow or if it's unrelated.