I'm assuming this is some kind of issue that has to do with the object's properties not aligning with like items to move it into a stack, but this is something that has been a problem since before the Definitive Edition was released. So busy with work, I've been unable to play much since the release of the Definitive Edition, but after downloading it again several days ago I had hoped this was something that would have been addressed.
It's not a huge problem or anything, but it's frustrating to have slots in my inventory filled with items that should be flowing into a stack.
You can see in the screenshot that some like items will stack, but not all.
Is this just me? Is this intentional?