The "Enchantment active status" does not get saved on an entity and thus gets lost when saving and reloading.

How to reproduce:

I've attached a datapack that adds a test:speed_toggled enchantment that adds a attribute modifier increasing the movement speed when stepping on red concrete and removes it when stepping on blue concrete, using the "enchantment active status" to keep it active in between.

1. Create a world with the attached datapack
2. Enchant any piece of armor with the test:speed_toggled enchantment and equip it

   /enchant @s test:speed_toggled
   

1. Step on red concrete
     You get a speed boost
2. Step off the red concrete
     You keep the speed boost
3. Close and reload the world
     You no longer have a speed boost