Junk to Trash

When I delete ALL Xfinity junk emails to trash, the trash file always contain 1-2 emails that were not in the junk. It is always from the same sender that are added to the trash from junk files. The involved senders have been blocked and reported to Xfinity via their missed spam function multiple times. This happens on both my iPad and iPhone. Any help/insight how to stops this would be appreciated.