All Junk Folder not working properly on iPhone 18.0.1

On my Mac, I’ve set up a smart mailbox for gathering all the junk mail from the several email accounts that I have.  It works well.  I have attempted to do this on my new iPhone. In the Mail app under mailboxes, I have added the All Junk mailbox. If a piece of junk email is showing on one of the email accounts that I manage, the All Junk mailbox shows a number corresponding to the junk mail that is in other accounts. However, when I open it, there’s no mail.  If I go to the account that actually has the junk mail and open the junk folder, I see the junk mail and then if I go back to the All Junk mailbox, that email shows. This makes the All Junk mailbox kind of useless.