There's a bunch of bugs in Plex for Shield (uncorrected in the latest version) that mean that Plex DVR on the Shield is currently UNUSABLE in the UK.
Videos recorded in HD hang on ff/rew, and sometimes fail to start: https://forums.plex.tv/discussion/257232/bug-android-tv-player-unusable-for-plex-dvr-hd-recordings-in-uk
Videos recorded in SD fail randomly part way through: https://forums.plex.tv/discussion/258640/bug-1-4-1-fails-catastrophically-half-way-through-plex-dvr-sd-file-uk
They can't always be optimised as a work around: https://forums.plex.tv/discussion/258645/bug-1-4-1-optimising-plex-dvr-sd-video-fails-with-transcoder-error-uk
Can someone from Plex at least confirm that these problems have been noted and are being worked on?