I had one of the faults for a single bank. No issue with the car running and like yourself, I reset and the CEL would come back on after a short period of driving.
Sourced a cheap enough Replacement O2 sensor, but I ended up selling the car before I fitted
I'd be tempted to try replacing one of the O2 sensors and see if you lose the codes relating to that bank.
Can't recall where I got mine from, but varied massively in price, that I do remember.