Sorry for the slow reply! The code you've created is completely untouched - I reverted all the changes after messing around (even replaced the 01_virtual_cursor.rpy file with an untouched version just to make extra sure). The place I'm seeing this behavior in-game is during an investigation segment which uses image buttons inside a screen. This code is in screens.rpy and it looks like this:
I'll then call the screen in-game and use a series of labels to jump to each event like this...which I'm just now realizing is exactly my problem!!! When the event jumps back to the broom_nav label, the screen is called again, resetting the position of the cursor.
Clearly there's a better way to code this that I didn't come up with the first time around (I'm self taught okay...) so I'll look into that! If you have any pointers you'd like to share, I'd really appreciate it. Otherwise, no pressure! You've helped me enough by making the perfect expansion :-)