Oh, the persistant text across the different drop down options in Notes/Subtitles...
I think it's related to if one of those options isn't selected. eg. i tried again and if i have
no track selected, going from project notes to track notes will keep the project notes entry persistant too. It does say "no selection!" next to the drop down menu, but obviously this can still be confusing if you don't realize that the text staying there is a bug.