Minecraft Version

1.20.1

Modloader

Forge

Modloader Version

47.4.2

Mantle Version

1.11.61

Tinkers' Construct Version

3.10.1.76

Describe your issue

When falling from some specific heights into earthslime you recieve the effect after hitting the ground and taking damage (this has been confirmed via a debugger).
These heights, measured from the bottom block of earthslime for a two block deep pool of earthslime, are: 46, 48, 57, 59, 64, 66, 71, 76, 81, 84, 89, 92, 94, 97, 100, 103, 105, 108, 111, 114, 117, 120, 123, 125, 126, 128, 129, 131

Steps to reproduce

Stand in a two block deep pool of earthslime and run /tp @s ~ ~117 ~, then while falling run /effect clear to remove the previous bouncy effect. This a so affects mobs.
If you have the bouncy effect when you hit the ground you bounce as expected.

Crash Report

No response

Can you reproduce with just Tinkers?

I have not tried

Performance Enchancers

Rubidium/Embeddium

Other mods

No response

Searched for known issues?

I did not search

Yeah, I don't think this one is fixable. I tried marking earthslime as a fall distance canceling fluid, and all that did was make you never bounce, but you still die at those specific heights. You will probably find there is a Forge issue here to report regarding that.

Seems fall distance resetting from fluids is run in a location hardcoded to water (well the water tag, but we all know why adding to that is bad). Meanwhile, entityInside will often run after the collision that causes fall damage at those specific heights.

Your best bet is just placing a block below your earthslime that also bounces you. Between the two you will hopefully get the bounce you want.