Deleted (and Moved) Messages not removed some folders

Outlook 2016 using Windows 10 Home:

When I delete or move messages from some of my folders (Sent, Draft, and a few others), the message is not removed from that folder. The message is struck-through, but stays on the list. When I click on that struck-through message, it opens up.

When I delete or move messages from other folders (Inbox, etc.), the message is removed from that folder.