Salesforce added '-setup' to the url as they are now hosting the setup on new domains
https://help.salesforce.com/s/articleView?id=release-notes.rn_general_setup_domain_prepare.htm&release=246&type=5
https://help.salesforce.com/s/articleView?id=001395243&type=1

for example:
https://miso-hello-995-dev-ed.scratch.my.salesforce-setup.com/lightning/setup/SetupOneHome/home

@motiko help!