Is Plex Media Server running on the Mac or on the Synology?
If on a Mac and experiencing trouble accessing media on a Synology, see Plex Files Unavailable but they’re not missing. It seems there is a problem with the SMB stack in macOS. The workaround is to use NFS instead of SMB. The thread also mentions nsmb.conf modifications that seem to help.
The TV is from 2014. That Plex client is no longer supported. You will need to acquire a streaming stick/box (Amazon, Apple, Roku, etc.) that runs a current Plex client.
Plex supports Samsung TVs from 2016 & later that run the Tizen OS. See Which Smart TV models are supported?
Your TV, an H series, is from 2014. See What Model Year is your Samsung TV?
Pre-Tizen Samsung TVs used a Plex client developed by an end-user, not by Plex. The app has not been updated in several years and no longer works with current versions of Plex Media Server.
