Thanks! This is also what solved the issue for me. Strange because I don’t remember ever setting up SElinux yet for this server…I could have swore I just skipped it because I’m just testing LibreNMS out right now.
For clarification for people that are still trying to fix their installations, I only did the steps included in the screenshot: 
After those commands, LibreNMS loaded right up in my browser (no need to restart anything).