Carpet stops slowness effect of soul sand (Re-post)

I am re-posting this because I had no chance to defend MC-103194

Placing carpet on soul sand causes the slowness of walking on soul sand to not be applied.
To Reproduce:
1.Place down a few blocks (soul sand and another block) in a line switching between the two of them.
2.walk across the line without carpet,and the with carpet on the block

Yes, I know that soul sand is not a whole block and carpet has a hit box that stops me from actuality walking on soul sand, but other blocks (ice, slime block, magma block) keep their effects when carpet is on top of them so I felt this is a bug because of that.