When you connect a custom domain to your site, you're changing its DNS (Domain Name System) settings. These changes can take anywhere between 24 and 72 hours to start working properly. Domain providers refer to this waiting period as "propagation time," or the time it takes for changes to update throughout the web.
Additionally you can also check if you set up your domain settings in the right way. Don’t forget to:
Set your domain DNS settings on your provider's site.
Enter your own domain in UXfolio Portfolio Settings.
Check the correct setup here.