I am noticing same issue after upgrading from 6 to 9.5
now if there is an instrument track with mute automation in the project and i solo any track on project window, than click solo again it mutes that track and all other tracks remain muted rather than unmuting all tracks when i unsolo. To unmute everything i have to now click on the unmute all solo states button at the top of screen which is super annoying.
THis cant be right, there is no logical reason for this behavior. Is there any way to fix?