When making SD card 'adoptable storage' on Marshmallow, Plex doesn't see it. So I Can't sync to it.

I have an Nvidia Shield Tablet K1 running Android 6.0
Android 6.0 is supposed to allow "Adoptable External storage to behave like Internal Storage"
The problem is that Plex doesn't see the new larger storage. It only sees internal storage. I have to go to settings and move the Plex app to the SD card. Only then will Plex enable me to sync to the SD card.
A huge downside from this is that every time the Plex app updates, it moves Plex back to Internal Storage, and I lose all of my settings and sync'd data...