FQDN == Fully Qualified Domain Name.
I suspect the issue is that:
- checkpoint.com resolves directly to an A record (i.e. an IP address)
- community.checkpoint.com resolves to a CNAME (i.e. an alias that, in this case, points to another alias, which points to multiple IP addresses)
I assume if you put the hostname that community.checkpoint.com ultimately resolves to, which is d2m0sklryvkyy2.cloudfront.net, that will work.
I did find one TAC case that suggests this should have been fixed at some point.
Please engage with the TAC, but meanwhile you can employ the above workaround (use the host the CNAME record ultimately resolves to).