How is size determined in UMG Wrap Box

I created a UMG widget for some inventory items.

I then made a UMG Wrap Box inside of a Scroll Box to display them. I am programmatically adding these widgets for each inventory item.

However I can’t figure out how it determines the size. There seems to be no way to tell the Wrap Box how large each slot is. I was looking at this which is returned when adding a child to a wrap box.

It seems to automatically compute it somehow. I have some text and an image in my inventory item widget and it seems to take a minimum height needed for the image but some random width to fit the text. As a result I get these wide but short boxes instead of square boxes that are sized according to some specific size.

The widget I’m trying to add. (It’s just sized using preview size, ideally I’d give it any arbitrary size)

How it looks.

I got it working by wrapping the outer canvas box of the inventory item widget with a size box. Phew, I’m starting to get a hang of this UMG stuff kindof.

It’s actually not completely respecting it though. For some reason some items are a tiny bit smaller. The first item is the correct size though.