Latest 1.20.1 version (1.22.9)

The collidable hitbox randomly becomes very janky and it becomes impossible to stand solid on it before slipping through the shown hitbox (using f3) or falling straight through. Also generally when dismounting the height at which you are put is slightly too low and sometimes results in falling straight through. You can avoiding falling through by spam jumping but even then sometimes they just swim out from under you.

Ultimately to avoid this bug I just hold space when on laviathan, though it would be nice to be able to use it as intended.

Sometime's they do little micro-bounces on top of the liquid and when that happens you fall through too. I'm not sure if you only fall through when they're bouncing. Sometimes it does just work as intended (very briefly)

It seemingly works PERFECTLY on land <3

Side notes: it would be nice to be able to dive once saddled, to be able to "tame" them as the wiki says you can and put domesticationinnovationcollar tags on them (Right now its just ridable, my underrated laviathan o7 ), and finally for the laviathan to not move on its own when someone is on its back (whether they are riding or just standing on hitbox)