Glad you are seeing some improvement!

That is right where the pec minor attaches, so my first inclination would be the smashing as well.  Have you included your delts in your smashing? If it just turns out that smashing isn’t accomplishing much, shift to more band work and see if it’s more helpful.

This episode has some good shoulder mobs that you might find helpful in that area:

If the ache continues, I would recommend a trip to see a physiotherapist.  At some point it becomes more sensible to save yourself the time and effort and simply ask someone who maybe able to set you back on track in a few minutes.
Keep working at it!