Issue:

When falling on a typical slime block, the user is bounced back into the air, preventing any form of fall damage, however, if you crouch and maintain that position prior to landing on the slime blocks, you take fall damage, potentially being fatal. Uncertain if this is an intended function of the slime block, or if is something worth looking into. Falling from maximum velocity causes instant death, including after up to 3 bounces to reduce maximum height on each bounce.

How to replicate:

Place a slime block, and fall on it from any height above 4 blocks, and hold shift while landing, fall damage is observed.