The "Unread" Smart Mailbox now includes unread Junk email
Starting sometime recently - not sure when but in the past month or two - the Smart Mailbox "Unread" in Apple's built-in Mail App began including junk mail. This appears to only happen to mail sent to my iCloud account (relevant because others have posted that this issue can be fixed by changing the IMAP prefix, but you can't do that with the iCloud account). Obviously this defeats the whole purpose of the smart mail filtering and the junk mail filtering. 90% of my unread mail is really junk. This never used to happen, so I presume it is a glitch from an update. But I can find no settings to address this. Any ideas?
Monterey 12.6.3
MacBook Pro