I figured it was worth mentioning here so players do not have the same problem I did.

As many noticed there is a gear restriction now requiring a certain mission to be passed to equip gear types. What is not shown however, is Battle Sprites follow this same rule and there is no indication of it doing so.

The requirements are:

- Mission Rank of 3-1 is required to level your Battle Sprite to 15 (2*)
- Mission Rank of 5-1 is required to level your Battle Sprite to 30 (3*)
- Mission Rank of 6-1 is required to level your Battle Sprite to 50 (4*)
- Mission Rank of 8-1 is required to level your Battle Sprite to 75 (5*)

If you do not meet these requirements, then your sprite will become unable to be fed its favored item to level up at all.

So if you find yourself unable to feed your pet for any reason, check its level and mission requirement to make sure you're not at the equipment restriction!