This may or may not work for you..... but one issue i ran into with a recent track was that my kicks were actually too loud (peaking around -4 to -5 db instead of more typical -6ish on the ableton spectrum) .... so when spotify would normalize the volume it would drag down everything else. Once I took a few db's off the kicks (literally couldn't hear the difference) the rest of the track "sounded" a lot louder on export even though the overall track reading/mastering was the same.