I changed the subdomain for my new hub site from hub.arcgis.com (default) to opendata.arcgis.com and now AGO/Hub say site cannot be found. The URL for the hub item on AGO is still pointing to hub.arcgis.com and not opendata.arcgis.com. I can get to my opendata.arcgis.com site by typing in the url but not within AGO and Hub.