I accidentally added a redirect to www.subdomain.domain.com, and the removed it from the web.config. The server continues to send the 301 Moved Permanently header. This is an ancient version 8.5 running on Windows Server 2012 R2. I cannot get it updated. The system is running on Azure.
I've done the following
Any other suggestions would be appreciated
It turned out that the problem was in the CMS, Kentico, which has an option to force WWW. I turned that off and will retry the move.