Have you tried this solution?
It will basically clear your launcher settings and all cookies, so you will need to re-authenticate again but it can solve some problems.
I have attempted to file twice, but afterwards, they do not show up in “My Bug Reports” list as even having been submitted
Bug reporting site has really short time-out so if you spend more than 5-10 minutes writing report, there are high chances that submitting will fail. That’s why you don’t see anything in “My reports”. To avoid that write report in notepad, then copy and paste contents into forms.