After IP change Defender locks me out

I set very strict lockout rules on my multisite due to constant login/404 attacks: ban permanently after 2 login attempts. Today my ISP had to change my browsing IP and now Defender locked me out, although I had not even logged into the backend. I have now disabled Defender by FTP. and at least I can log in as admin again, but as soon as I enable Defender, I get locked out.

I have another website that locks me out and I had to disable Defender, but I can't enable it again without getting locked out.

How can I rectify this? Is there a way to add the new IP directly into the database?

I have granted support access to my site.