Automated file tagging - Can't add a tag

I am trying to configure file retention.
I added the Automatic Tagging app to add tags to all files uploaded by a group.
I then attempted to add a rule.
I enter the description = success
I enter the tag = fails.
When I enter the tag it says “searching” and then changes to not found.
I had assumed that if I hit the tab or enter button that it would fill in a new tag. However, the field simply goes blank.

Apparently, I cannot add new tags to run rules against.

I have tried it in Chrome, Edge, Firefox, IE, and on my Android phone with the same results.