Suitcase Deadlift Revealed Large Imbalance

Last summer i was conventional deadlifting 405x5x5 after a few weeks i had so much pain in my right lower back i couldnt lift 315 once took a break from deads for 6 mo coming back in with somewhat less pain decided to do some deadlift variations to get back into it (snatch grip, suitcase and below know concentric pause) now i noticed this huge imbalance of strength from my right injured side to my healthy left side and im not sure what to think of it or how to handle it any other variations or drills that could help?