When playing a video or music via DLNA from Synology NAS the Samsung TV stop and steps to the next file if you have paused it for 30sec or more. People are talking about this “feature” on synology forums: Error when pausing for too long. When resuming it plays for 10-20sec then stops.
On way to prevent it from stopping after a pause is to make a step forward or backwards, then the connection will not be lost.