"Change Site Association" not working

As i wanted a secure site, i recently rebuilt my website with "Website Builder" (original unsecure site was built with "Sitebuilder Plus").  The new site loads fine and is indeed secure.  But i'm unable to get the site to load after "changing the site association" in "Domains".

The new website address is https://nbheartbeat.homesteadcloud.com/   and i want my domain www.NorthBayHeartbeat.com to direct to the new website.

I logged into my account, went to "Domains", clicked on "Change Site Association" for www.NorthBayHeartbeat.com, selected nbheartbeat.homesteadcloud.com

(originally was set to northbayheartbeat.homestead.com)  Now all i get is "ERROR 1001 DNS resolution error"  

I also have another website with exact same issue after rebuilding it with "Website Builder". I need www.McleodandYeates.com to direct to the newly constructed secure McleodandYeates1.homesteadcloud.com 

Any help would be much appreciated.  (Note: Sites both work fine if i change "site association" back to original "Sitebuilder Plus" constructed sites)

Thank you in advance, Barry