Now seeing this for the second time. User has to clear cookies before a sub-site using domain mapping can be seen.
Tested the same site in two browsers:
* one where the site admin was used
* one where the site admin was NOT used
Site loads fine when site admin was NOT used, but not the other way around. When using a browser previously using for accessing the dashboard, the site spins in constant redirect loops, finally resulting in an error page and this URL:
Clearing the browser cookies restores access.
Maybe this ticket should be moved to Bug Reports? Have seen it happen before and its a bit of waste of time explaining to clients why it happens, so I hope it can be addressed. Thanks!