The Bug

Putting on soul speed boots while standing on soul blocks gives you no speed. Likewise, taking off soul speed boots while standing on soul blocks doesn't take away your speed until you move off of the block.

Steps to Reproduce

• Replace the ground beneath you with some soul soil.

   /fill ~-2 ~-1 ~-2 ~2 ~-1 ~2 minecraft:soul_soil
  

• Equip some boots enchanted with soul speed whilst standing on top of the soul soil.

  /item replace entity @s armor.feet with minecraft:golden_boots{Enchantments:[{id:"soul_speed",lvl:3}]}
  

  → Notice how the soul speed enchantment effect is not granted until you begin moving.

• Remove the boots from your feet whilst the soul speed enchantment effect is active.

  /item replace entity @s armor.feet with minecraft:air
  

  → Notice how the soul speed enchantment effect is not removed until you begin moving.

Observed Behavior

Equipping or unequipping boots enchanted with soul speed whilst standing on soul blocks doesn't correctly grant or remove the soul speed enchantment effect.

Expected Behavior

Equipping or unequipping boots enchanted with soul speed whilst standing on soul blocks would correctly grant or remove the soul speed enchantment effect. Upon equipping some soul speed boots whilst standing on soul blocks, the soul speed enchantment effect should be immediately granted without having the need to move. Upon unequipping some soul speed boots whilst standing on soul