Can you provide a Report ID to start, and also clarify that this is when you just look in My Library? This isn't something anyone else has reported. (In some older versions, items across libraries could show up for an advanced search, but that's been fixed.)
Yes, could you take a couple screenshots or a screencast that shows this and email to support@zotero.org with a link to this thread? (Or if you don't mind sharing publicly, you can post to Dropbox, etc., and a provide a link here.)
Thanks, I think I figured out my problem. I deleted several collections thinking that all of the items deleted also, but they do not. I needed to delete them in the center window as well.
In Zotero connector for Firefox 708225600
Both say no error logged. I can send a screenshot if needed. When "My library" is selected, My group library items show up in the center window.