Are you guys familiar with this thread over here? It sounds like OP has stumbled on the thing we all stumbled on a couple months ago: A recent update to Chromecast w/ Google TV has made it necessary for users to go into the dev mode and turn off HW Overlay in order to stop Plex from dropping frames.
@theonematt - try accessing the developer’s menu on your Chromecast w/ Google TV, go into those settings, find “Disable HW Overlay” and tick that setting. Chances are pretty good you’ll have smooth playback again. The downside is this setting does not survive reboots or power-offs, meaning if your chromecast gets turned off, you have to go into the dev menu and reselect “Disable HW Overlay” to get Plex to work as intended again.
