In 1.16.2 when you have levitation and are shifting you are unable to float off the block you are on. This is possible in 1.15.2 and you are able to walk off it but not in 1.16.2

Recreation

1. Open 1.16.2 go into a world with cheats enabled.
2. Then find a drop of a few blocks
3. Place a block above you head
4. Give yourself levitation `effect give @s levitation 10000`
5. Hold down shift and try walk off the block.