If you need support from Yola please contact us via firstname.lastname@example.org or make use of our live chat service! We are working on a new approach to community-based support and during this transition period we are not adding any new threads to this forum. Many thanks to everyone who has participated over the years and we look forward to unveiling a new peer-to-peer support system soon!
I have just answered your support email about this. Everything should be working now.
For the benefit of anyone else with the same problem: This happens when you have configured your DNS correctly by setting up an A record to point to SynthaSite, but you have not yet published your site to your own domain inside the SynthaSite site builder.
This is a common problem, so thank you for posting the question. I am sure it will help other people as well!