To fix plexmedia server “indirect” issue you need to do this:
Go to: 192.168.1.1 web interface: Network->" DHCP and DNS"->“Server Settings”->" General Settings".
- If you have enabled “Rebind protection” then change "Domain whitelist
" field by adding this: “plex.direct”. Save settings. - Refresh webpage “https://app.plex.tv/desktop”
- Additionally you should have enabled portforwarding for plexmediaserver.
This fix worked with Linksys WRT3200ACM-EU, Openwrt 18.06.2 r7676.