So, this is on a random cloud server, it was with AWS lightsail server first. It had the same problems. Now it’s a new installation on Ionos.com. Each has had the same issues. I don’t think it could be a NAT problem because I’m not behind anything but the simple firewalls. On the lightsail server, it was only behind their firewall (not even the linux one) which I had allowed the ports through. Now on ionos.com I thought it only had the UFW firewall but it also has one built in that I just found and so I allowed the same ports on that.
It’s set up with an A record pointed to the IP address. The A record is for a subdomain on my main domain.
In looking at the instructions to check the connectivity from @corby I wasn’t sure how local IP could do anything, so I put in only the command about the public IP and then it worked!
I’m reasonably new to linux and cloud servers. I’ve created a couple websites and a few re-streaming servers on the cloud using nginx. However I’m by no means an expert. I had programing skills back in the 90s but that was on Fortran. For the past 20 years I’ve been an aerospace engineer by trade and learning cloud servers in my spare time. Any help on these things is very much appreciated.
I think I have it working now! Thanks so much for all your help.
Now I want to update the system to make the home screen look a bit different and have organizational graphics. 
Can anyone point me in the right direction for any of that?
Thanks again!