Like the article says, it can take up to 72 hours for your domain to start working everywhere. It’s completely normal for a new domain to work on one device/network but not another one.
Setting up a domain on our end takes a few minutes at most. Everything after that is due to caching at client devices and networks, which is outside of our control. And, since it’s client side, different clients will have different experiences.
Please wait for the FULL 72 hours first. That’s how long it can take for it to work everywhere.