When I'm reviewing my highlights in the Comments pane and want to highlight something, keyboard clicking U instead creates a new comment. When I first select something and then click U.. it's striken through instead of highlighted? That is the opposite of what I'm trying to achieve!

I have to first cursor-select the Highlight tool to be able to properly keyboard switch again between other tools. I understand that giving U different functions in different contexts makes sense but this very much seems to be a bug.