Optimized Versions Playing By Default

I’ve been using the optimized versions feature to make 720kbps encodes readily available which I can quickly sync to my kids tablets without having to transcode everything each time I sync. One issue I’ve run into (intermittently) is when I play regular episodes through the web interface or on my Roku, Plex will stream the lower bitrate encode by default despite the fact that a better 1080p version is available and accessible.

Is this a misconfiguration on my part? I’m not doing anything special when I view an episode, I simply hit play and let Plex do its thing.

I forgot to mention I’m running the latest version of PMS on Ubuntu 14.04.

Version 1.1.4.2757
Linux media-pc 3.19.0-42-generic #48~14.04.1-Ubuntu SMP Fri Dec 18 10:24:49 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux