This can be problem with my account or website because this must be problem with cookies.
When I open community.amd.com website in private mode I can create only one subject or new post. If I want to create more than I can see information like this: "Post flooding detected (user tried to post more than 1 messages within 600 seconds)". Like I said when I want to create second subject or post this is not possible. I must log out next exit the tab and next open new tab with private mode. This can be also problem with new version of firefox 91.0 because before update to this version I had not any problem.