I had issues with connecting with OpenVPN client on android.
The workaround is to use TCP port instead of UDP port.
On the Vultr's Firewall group > change UDP port 1337 to TCP port 1337
On the Pritunl console > delete the existing server and create another with the same configs except change the protocol to 'tcp' instead of udp
You will have to download the profile again, and it works flawlessly !
Awesome guide btw !!