Walking on bottom half slabs with slime or honey blocks below it, slows down the player

I noticed this issue was reported once but got Resolved without the 1.21, 1.21.1 version mentioned and it is still an issue. (MC-1127)

Way to recreate this bug is:
1. Place slime or honey blocks on a flat surface

2. Place bottom half slabs on top of the slime/honey blocks

3. Walk on top of the slabs and observe the speed change