I've been gradually retraining myself after years (like 40) of wrong approaches starting with being taught to "strike" the keys at an early age. One thing that I notice is that I have much better elasticity and range of motion (with my fingers) in my left hand whereas my right hand I have trouble playing thirds (for example) because my I can't get enough height from my fourth finger to clear the key. I can't tell if its neurological or that the hand structure is really less flexible. I'm leaning strongly toward the latter case now but wonder what is a safe approach at imrpoving this.
Is your hand generally very low at the keyboard? Standing up and pivoting on any finger really could make a difference. Let us know how it develops.