Sq4nch
Hi there,
Plex DLNA may change the filename. Has the filename ("moviename.3d.fullsbs.mkv") changed when you play it from Plex DLNA on your Quest?
If the filename changed, SKYBOX may fail to recognize the file as FULL SBS. If the filename is still showed as "moviename.3d.fullsbs.mkv", SKYBOX should correctly recognize it as FULL SBS.