I recognize some website will use a subdomain for authentication and you want the passkey to work across them, but it is really annoying for me to login to certain services that have two or 3 services under 1 domain that do not link together, each has its own passkey.

The ability to stop the wrong passkey from showing up when logging in would be handy! Even just a "Ignore this passkey on this subdomain/url" option!