I have a number of boards that I’m the owner of, yet today I’m no longer able to edit or move the text on my connection lines. Double clicking on the connection line or its text just creates a new text. If I remove the existing connection line and replace it with a new one, I can edit and move the connection line’s text just fine, but the label on any existing connection line is just frozen. 

This is both in the macOS client and in the web interface.