That likely means your report triggered a malfeasance filter in the reporting form. For years now NVIDIA appears to have set the trigger level on that to insanely strict settings. So it doesn’t give any information away, one gets a generic error message when the filter is triggered. Frustrating, I know.
A common strategy to deal with that is to file a very rudimentary report first. Like a synopsis and a two-sentence description, with a comment that you’ll add more info later. In particular, avoid adding links or anything that looks like HTML to the initial report. Then come back to add additional information bit by bit. Yes, it is a pain in the neck.
Sometimes there are also technical issues of an unspecified nature affecting the bug reporting form.
FWIW, I noticed that your first post in this thread currently shows up for me as “flagged by community”. I doubt that anybody from the community has flagged it, as I see nothing objectionable in it. I suspect that it was auto-flagged by the AI (e.g. “a link in an initial post means suspicious”). I hope that this has not put your account as a whole on the bad side of NVIDIA’s machinery.