Item assigned to one site is shown in another

I have two sites that stem from the same Admin dashboard, let’s call them Site A and Site B. I’m trying to add items that are specific to one or the other of the sites, but am having trouble. Site A started first, so was the format for the first few items. But then when I went to add some items to Site B, it is still using Site A’s formatting and slug in the public view. I checked and the item and it’s item set are both set to Site B. I have unchecked the “Auto-assign new items” for both in their respective Site admin panels. I have also removed the default site that was listed in the Admin Settings area. But it’s still doing it–at least with older items. I haven’t added any new ones since this problem popped up, so I don’t know if that will change anything.

Did I do something wrong? How do I fix it?

Megan Styles