Thank you for your patience and we apologize that we didn’t reach your request a little sooner as we worked through the support queue.
We’ve taken a glance at your account details and see recent sign-ins on the aforementioned device - are you still having login trouble on your Mac? Please let us know and we’ll keep a lookout for your response.
One additional precaution you can take against login issues in the future is to verify that your router is using a reliable DNS server. In your router web administration page, try setting the DNS server to Cloudflare DNS, Quad9 or Google DNS. Can you please give this a try and let me know if it helps?