Repeating the steps in the first post works for me on a RTX 4070. Even when I use your screenshots to configure other things away from the defaults it works for me. I guess it depends on your hardware.
Changing things in Advanced mode requires your own trouble-shooting and not accepted as a bug. Advanced mode is designed to let you break things. There are too many variables to codify the rules to prevent that. And even if someone uses AI to generate a million new lines of code to add those rules, I do not want to try to understand it all to debug something. You troubleshoot it by reading the log.
I think there was a change in the past year to allow B frames with hardware encoding since a lot of hardware in the past several years supports that now. Combined with this