I have the same problem – When I start to play, at a point, a track goes into solo! I have unknowingly made a track "auto solo" and don't know how to undo it, as I've already saved.
RolynHenry thanks for the solution, deleting the automation is the option yes, but I don't really want to delete automation as I worked on it a lot. Is there any way to stop this soloing and keep the automation?
Please let me know.