Different issue from MC-44352.
If you hold an item in your hand and walk across slime blocks, the item can be seen to vibrate slightly. Items do not seem to do this on other movement-slowing blocks such as soul sand.
Linked issues
relates to 2
Comments 10
I have since been able to confirm one case where the effect only happened after sneaking but this was an isolated case.
Relates to MC-151706.
Only happens in the same circumstances as MC-44352 did: only after the player sneaks on the slime block.