I have this odd issue with Serenity on the AFTV.
I organize my movie media on the computer running my PMS on two hard drives and from those I have 2 movie libraries within the PMS (one named "Movies" and one for my kids movies called "Kids"). We also have a home video library called "Videos" (yea, I know, real clever of us).
On Serenity's home screen it shows the two fine, one named "Kids" and the other named "Movies". However if you select one the only movies that show up are within the "Movies" library. Again if you select "Movies" from the home screen you see all the movies within that library but if you select "Kids" you don't see the movies in that library, but instead see the movies in the "Movies" library. Same thing for the "Videos" library, select it and only the movie files within the "Movies" library are shown.
For the regular Plex app everything works fine. You select the "Kids" library and see the movies within "Kids". And if you select "Videos" you see the video files.