When trying to create a recipe with items that don't stack without changing its max stack size you get a error. However prior to 24w09a you could still make a recipe result with multiple of a non stackable item. They would come in a stack but couldn't be restacked. But now if you want multiple of a item in a recipe you have to allow them to be stackable. Preferable you would get a result of multiple of the non stackable item.

The error I'm getting.

Parsing error loading recipe datapack_example:recipe_example com.google.gson.JsonParseException: Item stack with stack size of 4 was larger than maximum: 1

The recipe with multiple non stackable previously worked before 24w09a and would come in a stack but couldn't be stacked up again.

Steps to recreate
1. create or load a datapack in 24w14a with a recipe that has a result of multiple non stack able items.

Result
2. You'll get a error saying "Item stack with stack size of 4 was larger than maximum: 1

Expected result
3. The recipe will work and you'll receive 4 items that won't be able to be stacked. 

I have uploaded a example of 1.20.4 and 24w14a recipes. Also uploaded datapack examples in zip files. I understand that 1.20.4 gives you a stack of the items however once unstacked they cannot be restacked together. A preferred result for the new system is it puts them in separate slots of the inventory instead of stacking them. If the item stack is default at 1.