Whilst I can't offer a diagnosis - if you haven't already you should probably visit a sports physio to get it assessed (you can find certified sports physios in your area via ACPSM - - Association Of Chartered Physiotherapists In Sports Medicine (ACPSM)
In the meantime, you can continue to do front racked barbell lifts by adopting an alternative technique for front racking the bar - just rest the bar in the same groove between deltoids and collar bone and cross your arms in front, keeping your elbows level with or above the bar, and rest your fingers (palm down) on top of the bar. If you search front racked barbell in google images an image to show you should come up on about page 6.