If you have several Apple devices and use the Safari browser, iCloud tabs is a convenient way to access web pages you’ve got open on another device. A common problem is that when you close a tab on another device it keeps showing up on other devices. It seems that when you close a tab and connectivity is lost to Apple’s iCloud servers, the closing of that tab is never registered.
On a Mac, if you’re seeing phantom tabs from your iPhone or iPad, the easiest way to remove them is to reset the iCloud tabs database:
This approach is working on macOS Ventura 13.5 and iOS 16 and was originally seen here.