Exact same issues here. I had my whole unit changed on the first day I got it (23rd Oct), and even the 2nd unit also had the exact same issues. Noticed that my wife's pair has no such issues and the serial numbers on her buds start with GW/GX. My 2nd pair was GN/GN.
Within a few days, I returned it as i thought it was a batch issue. After some thought, tried to look for the batch that is close to hers based on the serial number on the box. Found one (GH), bought it and the issue didn't sound as bad as the first 2 pairs (first 2 pairs you could literally hear the singer's voice travel down to the bottom left side!) My 3rd pair the serial numbers of the buds were GX/GN.
Yes, I'm conclusion the sounds seem more balanced on both sides if ANC/Transparency modes were turned off. It was the worse in ANC mode; I had to keep re-inserting and adjusting into my ears, and even tried to equalize my ears for it to sound bearable in ANC mode. If I keep switching between the 3 modes, there's an obvious shift in the sound balance.
I'm thinking is it because I have heavier tinnitus in my right ear that is causing this issue? My wife tried my pair but she feels that both sides seemed balanced. If there's some way to turn off the auto-sound adjustment (or wondering if it's the Adaptive EQ?), I think it'll be perfect