AWS has a tool to convert EBS volume device names in /etc/fstab to their UUID values: c5_m5_checks_script.sh
The script also checks that the NVMe module is loaded in your OS image, but your newer instance type would not have launched if that was not present.
I expect that the confusion is coming because you are using both UFW and IPTABLES. UFW is a front-end for iptables, but if you add rules outside it I expect that it can't recognises those rules.
Thus you are not seeing the iptables rules injected to handle your OpenVPN connection.
I expect if you list the iptables rules you will see them. Try
There are other scenarios where this is a useful trick and the method I have used in the past assumes a fairly standard internal network behind NAT and will work with any computer with any OS. I will assume that your network with internet access is on 192.168.1/0/24 and your private (offline) network is on 10.0.0.0/24.
Get hold of a normal internet router. ...
For the PHP-FPM status page to work properly under nginx, the following parameters must all be set:
fastcgi_param REQUEST_METHOD $request_method;
fastcgi_param QUERY_STRING $query_string;
fastcgi_param SCRIPT_NAME /status; # see notes below
fastcgi_param SCRIPT_FILENAME ""; # see notes below
REQUEST_METHOD and QUERY_STRING are set ...