Ok thank you @gotwf

Also looks like I spoke too soon - regarding your original question 1, if I bypass nginx and connect directly using the server external ip to port 4567, I can see nodebb launch "correctly". But if I access it through the domain name, it gives me the above result. So that did matter.

Here is the nginx server block (file name - forum.kado.ai.conf)-
ef212ef4-08fe-4d4c-91d0-3a33796fd31c-image.png

Here is the nodebb config file.
07aefd27-b7e6-455c-a0e3-25551b48b7f8-image.png

Thanks again!