Help with Integrating Squarespace into Instagram Shop

I am trying to integrate my squarespace products onto an instagram shop. I sell unique items, so most things only have one variant, size, color, etc. For example, I will sell a vintage jean jacket. I am having a hard time getting my clothing items to appear in instagram. The homewares I have appear fine, but instragram is flagging all of my clothing items saying there is no size listed. I have sizes in all of the product descriptions, but I guess because I don't have a special size field in my squarespace products, the data isn't pulling over into instagram. I thought about adding a size variant so that instagram would have a better way to pull the size. However, I cannot add this since squarespace won't allow just one size variant.

If anyone has any advice, I would appreciate it. I tried just adding the sizes to the instagram products themselves which worked for a few minutes, but they ultimately do not save because the integration from squarespace keeps overriding any changes I make.

Also, if anyone knows how to have the same advanced shipping selections that I have made in squarespace pull over into instagram, that's something else I am struggling with. Thank you.