Log in with lightning are unrelated to Nostr. I don’t know exactly what you did, but I assume you by accident created new master key (eg by reconnecting your account or reinstalling extension). Remember, Alby does not have your keys and each time you connec your Alby Accounts you need to manually import our keys (Nostr and/or master key). Do you have your master key you used for lightning apps saved? Maybe try importing it