Rewind song.
Open the Event List for a given track.
Look at the control change events for the track that happen at the beginning of the song (and thus reset whatever you did).
CC 11 and CC 7 both affect volume, and could also affect PT sliders.
Delete these events (then use Save As), test, and then set your volumes.


Make your sound your own!
.. I do not work here, but the benefits are still awesome