I've probably clicked somewhere I shouldn't but ALL of my tracks are seemingly linked together. If I solo,mute,or just delete a track, it affects all of them. What have I done???
A real bad one, I'm afraid. Clean install of Windows and applications. Maybe also drop in some new hardware for good measure.
Or just single click on an empty space between icons on ONE track's header or whatever that area is called (the left-most box with sliders, buttons, etc.). Happens to me from time to time. Danged frustrating when it happens unintentionally.
(Maybe you selected all events and pressed "G" for group? If so, select all and ungroup.)