“My website's not working... heeelllllp... !”
Different browsers will indicate errors differently. The messaging I'm using here as examples is specific to Chrome on Windows.
Aka "Refused to connect."
DNS changes can take awhile to propagate globally. Your TTL settings will affect this, however many providers still do their DNS updates in batch at ~midnight.
If those are Connected ok, then your browser make be showing old data.
Web browsers and OS-level network layers often cache DNS requests, such that even a hard refresh of a page might not give you the current live content. Your browser's refreshing, but it's still trying to retrieve the page from an old server location.
Let's see if it's working for everyone else.
https://downforeveryoneorjustme.com/
If it's just you, your DNS and hosting are fine. Your browser and network adapter, even a proxy server may need to clear their caches so that you're getting current content.
At the browser level, here are the instructions for Chrome/Win, you'll need to adapt these for your own browser.
If you've just enabled SSL, it takes a bit of time for the certificate to be provisioned. Give it an hour and check again.
https://toolbox.googleapps.com/apps/dig/
https://downforeveryoneorjustme.com/
https://www.whatsmydns.net/