Dupe Sent Messages Folder in iCloud

I'm just trying to figure out why I have two folders called "Sent Messages" that populate as choices in the Mailbox Behaviors settings.

The one that has a regular folder icon, rather than the paper airplane, seems like it was manually created, but I know I haven't manually created a duplicate folder.

This duplicating is true for Drafts as well.

I see both folders in the Mail client (Sent with paper airplane icon in the Favorites area and Sent with folder icon + email@mac.com in the iCloud area). Why would two Sent folders and two Drafts folders exist?