It's a bit strange Nanu admittedly. If it were me I would understand, as in "we don't really want you here". I had it a while back when every time I logged in I had to confirm I wasn't a robot; it said something about logging in too often. I could understand that.
A glitch in the matrix maybe?
Seriously though, have you had any other issues with emails, social media, etc? Your details may have been compromised elsewhere and it's showing up on the embedded security of this site? I don't know anything about this type of thing so am just guessing

All good things come to those who wait. I'm really impatient which explains a lot.
2024 Audi A4 avant 40 black edition petrol
2025 Ford Focus ST 'track pack'. Go-kart with sat nav.
Z3 'free litre'. Project and a half.
No Z4 anymore!