Can view library just can't play anything remotely

Server Version#: 1.23.1.4528
Player Version#: 4.55.1

Reloaded DSM 6+ from scratch on a 918+. Installed Plex on Synology. The online version was 1.18.x.x.

I tried to enable remote access after setting firewall access and port forwarding is set on router. I wasn’t able to view my library remotely so I updated to the latest server version.

After updating It says ‘fully accessible outside your network’ but there is no green check mark next to ‘remote access’. I manually configured the port to 32400.

Everything is greyed out on the 'Private ->Public->Internet. When I log in and connect remotely I can see the server and the libraries.

When I choose a show or movie it pulls up and you can hear the theme music but when I hit play, nothing happens. It’s like the play button is frozen or something.

Can’t figure this out. I have loaded and configured Plex servers probably a dozen times for friends and family and never had an issue.

Any Help is greatly appreciated.

Mod: Edited for clarity

See attached log files
Plex Media Server Logs_2021-05-19_20-50-34.zip (4.3 MB)

After following your instructions I click ‘apply’ on the manual configuration and it will sit there forever spinning ‘connecting to server’