DNS configuration for WHM / CPanel not working on all networks

EDIT(Solution): I got some help on the cpanel forums and found the problem. When I setup my domain DNS records through linode it automatically created AAAA records, but my WMH server wasn't configured for ipv6. So on one machine requests were going through ipv4, which worked, and on the other it was doing the requests over ipv6, which failed. I just deleted the AAAA records and things are working now.

I'm configuring a cpanel linode server and having trouble getting the DNS settings working.

My Setup Steps

• Point my domain provider to the linode name servers (ns1.linode.com… etc)

• Under "domains" I have created the default records for my domain and A/AAAA for my FQHN that I setup in WHM e.g. mydomain.com, prod-01.mydomain.com

• I have set my linodes rDNS to my FQHN

• I have set my WHM default nameservers to linode nameservers

• In WHM I have created an account for my primary domain

• WHM is configured to not run its own nameservers. The account is set to use the linode nameservers by default.

• I put a test index.html under ~/public_html

Results

When I test this on my home machine I can successfully access the website from https://mydomain.com

However on a different machine on a different network I get redirected to the default cpanel page /cgi-sys/defaultwebpage.cgi.

So something is up with either my DNS configuration or the vhost config right? I've attempted to setup additional accounts on subdomains and ran into the same issues.

I discovered this issue initially trying to setup SSL with LetsEncrypt because the challenge requests to my domain were coming back 404. So its not just the machines I have tested.

What I have done to troubleshoot

• Verified with numerous online dns checkers that my dns records have propagated and my domain->ip should resolve correctly.

• Cleared browser cache/cookie and run ipconfig /flushdns on local machines

• Play around with A/AAAA/NS records on both the linode DNS manage and WHM DNS zones.

• Configured / disabled firewall

I'm new to DNS config and need some help troubleshooting this. Why might this be working on one machine but not another? Happy to provide additional details. Thank you