This guide explains what all the different terminology around custom domains means and should help you troubleshoot custom domain issues.
Domain - this your root domain e.g. mywebsite.com
Subdomain - this is the subdomain you want to set up as a custom domain e.g. videos.mywebsite.com
CNAME - allows you to "point" a Subdomain to another Domain. We use this so you can point "videos.mysewbsite.com" to us (pitchlane.video).
"Host" or "Name" - in "videos.mywebsite.com" this is "videos". It is not the full domain, and it is not the value/target of the CNAME.
"Value" / "Target" / "CNAME" - this is where to point the subdomain to. You should set this to "pitchlane.video".
Please note that some Domain providers may use slightly different terminology. If unsure, reach out to us.