Are you trying to register or log in?
My security dashboard shows that a large number of registration and log-in attempts have been blocked.
That can of course be correct (that is why I have installed security modules), but they can also be unjustified rejections.
During my tests, I didn’t yet discover anything, but still …
If you have difficulties with registration or login, use the contact form to notify me. With that function, no problems have been reported so far.