Hello!
You can add and then remove two stacks of them in the cooking stations

I know that it can happen in the cooking stations when you auto-add the ingredients to the slots, and one of the ingredients doesn't have the quantity needed, so you remove it and then manually add the correct quantity from a different stack, which leaves you with two stacks that aren't full. Not sure if that was the case with Eliatrope though.

@Eliatrope

I think Yingrella's fix is the easiest way to do it, because the only other way I can think of would be to place each item in your house and remove it until they're all in the same stack, which would be tedious. ^^;

Though it would be useful if there was a button or something in your inventory that merged partial stacks of the same grade (or lack thereof) instantly.

I'm specifically thinking about a similar issue on flightrising right now, but I think I've seen some variation of this happen on every pet site I've played? :o I wonder what it is with the item stack codes that seems universally moody