Put OurFunVaction on the timeline. Lock the Video Track. Select All (ctrl-A) to select everything that isn't locked.
Now try to deselect one of the audio clips - CTRL-click on, say the second clip. Why does the last clip also deselect itself? Could there be any reason why this is by design?
Same happens when you lock the audio and work with the video. It doesn't happen when you don't have a track locked.
S12.1 - but it also happens in S9, so I'm guessing 10 and 11 as well.