Following the instructions from this post I (as root) edit the /storage/.plexht/userdata/guisettings.xml file to set "shuffle" to true. I save the file and then verify that the file was saved by looking at it using less. In Rasplex I click on "TV Shows" and then highlight the series and press the Play button on my remote. The first episode always plays. When I go back to the /storage/.plexht/userdata/guisettings.xml file my changes have reverted back to "shuffle" being false.
Are the instructions in the above linked post even valid for Rasplex? If so, am I editing the right file? If I am editing the right file, how can I keep my changes being overwritten?