I also have the same problem. Lefty is definitely an overachiever and usually produces double what righty does. For a brief moment it was reversed and then I got a plugged milk duct on the right and it went back to being the slacker.
@Kelli Same thing happened to me. I try nursing baby more on the right side. He seems satisfied but when I try pumping I get nothing out even if I feel full but left side I get like 3-5 oz when I pump.
I have no advice but I have the exact same problem but my left one is a slacker! Midwife/health visitor told me it’s really common xx