Just added this to my Aberration SP game. All my tamed dino's started laying mantis eggs, but if you unclaim then claim the dino it seems to fix my spino, but not my raptor so far. I'll keep ya posted

last updates should have fixed it

There seems to be some kind of collision bug. After riding the mantis a certain problem occurs. When you run into/onto a structure with your character after riding the mantis, you begin to float and get stuck in the air. Also while riding on the mantis in the water (swimming) sometimes I got stuck on the water surface while mounted. Only solution to both problems was to type in cheat ghost command.

What might help you to find the culprit?

I experienced this bug with another mod long time ago. It was the Definite Otter Mod. The mod author was able to solve the problem quickly. Maybe you can ask him/her what made the floating bug stop. In the otter mod the floating after colliding with structures occured after hovering through the air while mounted on the otter with help of the space key.
Your mantis has a jump ability on space key. Maybe you can find something related to that which causes the floating.

Good luck and thanks for your hard work!

Otherwise awesome mod! =)

I have tested a couple of things. I deinstalled the mod and deleted the mod folder. I checked for corrupted files.

Then I spawned in a vanilla mantis on the island and after a while it shows, that the problem occurs as well, at least the water thing. I didn't have the floating issue after colliding with structures with the vanilla mantis, which I had with your Ultra Mantis. But it seems the water stuck issue is not related to your mod, but is a generell problem with the mantis. Maybe it's because the mantis was originally developed for an evironment that has no water --> scorched Earth.

I haven't tested the Ultra Mantis or vanilla mantis in Aberration though. Once I do that I'll get back and give a feedback in case it helps to improve the mod.