I have a question about http 2.0, I send the login form with http 2.0 and HTTP Debugger captures the traffic and I receive it with http 1.1, is this normal?
OB Send HTTP/ 2.0

HTTP Debugger Capture HTTP/ 1.1

I have a question about http 2.0, I send the login form with http 2.0 and HTTP Debugger captures the traffic and I receive it with http 1.1, is this normal?
OB Send HTTP/ 2.0

HTTP Debugger Capture HTTP/ 1.1

It could be a issue, try it on a different plattform (Linux) or make sure you installed the last OpenBullet version, if yes, then try previous versions of OpenBullet.
Try changing HTTP Library to SystemNet instead of RuriLibHttp.
yes is selected SystemNet otherwise u get error is not implemented http 2.