Hello @SupK,
Thanks for asking.
Did you mean that the old URL that was assigned to licence was changed with a new one? And after that you are experiencing slow load time while getting into login page? If yes, that’s quite strange.
Can you please try to deactivate all installed plugins and see how it goes? After that please try to increase memory limit. Click here for more detailed information and how to increase the PHP memory limit.
If you still face slow wp-admin load time, please share website login details (url/username/password) in a secure note for us to take a closer look.
Thanks.