What you quoted has to do with G-1145 (e-notification of application/petition acceptance) with I-129f, but filing I-129f online.
did you also try to call USCIS or chat with the agent online? I would try that as well and see what happens. If all of the above doesn’t work, then it’s time to contact your congressional representative or senators office and also submit a request with CIS Ombudsman. 6 months is too long to wait for NOA1.