I'm having the exact same issue for months now. Same codes. Would like to know what the issue is as well. What is your full exhaust setup? Also do you use a dp fix?
I've replaced front o2 sensors as well. Also reset lambda and AFR with no luck. Codes come back straight away.
Current: Mercedes CLA45 AMG, Porsche Macan S
Past: BMW 135i, BMW E46, Ninja 300 ABS