How To Fix Private DNS Server Cannot Be Accessed | Mobile Network Has No Internet Access | With VPN

So I noticed a couple months ago sometimes my private DNS was working and other times it couldn't connect (I had no internet). I thought, at first "Must Be The VPN!". So I just left my private DNS on automatic for the last couple months.
Recently I installed a new ROM, the super cool AICP! and I went through the setting, set it all up. Set up my private DNS and all was working awesome until I erased all the data (basically a factory reset because I was trying to get Edxposed to work which I could have sworn worked on this phone prior). Anyways I noticed for a couple days Private DNS was acting up like months before so I went through all the setting (when I had that notice "couldn't connect to private DNS"). When I changed something in settings I checked the private DNS. It worked once I enabled "roaming". Now mind you, private DNS worked just fine without VPN, but I like my VPN always on so I found out How To Fix Private DNS Not Connecting With VPN.
P.S. It could be that I am connected to a different country through the router at home and when I leave the house I like having my VPN the same country so, maybe, somehow, the Private DNS 'roams'? Not really sure. All I know is my Private DNS is working Beautifully with Roaming on.