So your native nginx process covers ports 80 and 443. which ports does your NPM use? Are you trying to use the same ports? Because that’ll most likely clash.

Joomla worked well for me.

The ones from the applications which should do the proxying and serving.

BTW: you’re using both Nginx Proxy Manager and Nginx in parallel? Native installations, docker, something else?

How are they configured?

Post more logs/configs