Can't publish the update because it says "That title’s taken, try another"

Summary

When I tried to update a map that I published just three days ago, I got the message “That title’s taken, try another,” and now I’m unable to publish the map. The map’s name is completely original and includes a proper noun, so there’s no way another creator could be using it.
Even after slightly changing the title as suggested by the message, I keep receiving the same error.
However, when I changed the title from Japanese to English — keeping the exact same meaning — the issue was immediately resolved.
This leads me to believe that there may be a flawed validation process specifically affecting Japanese-language titles.

Please select what you are reporting on:

Unreal Editor for Fortnite

What Type of Bug are you experiencing?

Creator Portal

Steps to Reproduce

Try to update a published map (uploading a release from the private version)

Expected Result

Allow titles currently in use to be used as they are.

Observed Result

"That title is taken, try another title.” will be displayed.

Platform(s)

all

Upload an image