Soul speed doesn't work when half-slab is on top

Summary

Soul speed doesn't work when you place a half slab on top of soul sand/soil like it does in the java version of Minecraft. 

Updated Description by JervieA20

Steps to reproduce

1. Set FOV Altered enabled in video settings to make fully visible
2. Use soul sand or soul soil and create a floor lane setup
3. Take any half size blocks like half slabs, trapdoors, carpets etc.
4. Place any half size blocks to top of soul sand/soul soil floors
5. Use any materials of boots and enchant with soul speed enchantments
6. Try step into soul sand/soul soil to half size blocks

Observed results

Soul speed no longer able affect to any slabs on top of Soul sand and soul soil 

Analysis

Comparison of half sized blocks

Expected behavior

 Soul speed can allow able affect half slabs on top of Soul sand and soul soil