Solved, thank you. For others having trouble with a Shield - I was not able to update Plex Media Server from the device itself in the apps list. It was diplaying it as if it was already the latest version. I got the update pushed without much problem via a web browser play.google.com, searching for plex media server. It allowed me to install it to my Shield as if it wasn’t already installed. And sure enough that did get me the update.
