I’ve found the solution if you have downloaded Google maps instead of bing. If so do this:
Remove the Hosts file altogether.
Restart PC.
Window’s will make a new one.
Large complex airliners do take 10 or more minutes to load for the first time.
If the issue still exists, start with this troubleshooter: https://flightsimulator.zendesk.com/hc/en-us/articles/4406039624338-All-versions-Loading-issues-Checklist