[mups]

I've had a similar problem that took me a little while to solve...
Sometimes I would find all the tracks selected, even though there was no active group.
It came from accessing a certain location by clicking in the line that is directly above the tracks, that while the "Link track and edit selection" function is engaged.
A friend finds himself in this little trap once or twice a year and he calls me to remind him that he has to deselect one track by clicking it while holdind CMD...