Hi @goavancer
As per my experience and knowledge this kind of issue occurs either from DNS side or something from the network end.
Do one thing try with some other network or by flushing your DNS cache - then it will works !
Make sure you have proper configurations in core_config_data !
Also please share the admin link if you can its possible to share so further its helps us to troubleshot the issue.
Hope it helps !
if issue solved,Click Kudos & Accept as Solution