Server Version#: Version 1.18.0.1944
Player Version#: Plex Web Version 4.10.1
Non-premium Music library (it sucks too much detail out of my library to use it)
Agent: Local Media Assets (Music)
Every recent album that I add to my Plex library has correct Genre tags in their FLAC metadata (confirmed with Mp3Tag), however, when imported there is no Genre tag filled at all in Plex (on the Tags pane or shown on the album screen). The last one that worked was imported with Server Version# 1.17.0.1841, then I updated to 1.18.0.1944, and none since have any Genre.
Don’t forget the post one down in that thread by a Plex Team Member
Apparently there’s some dastardly, unknown danger in changing the settings, so if you’re like me, expect the genres to be broken at some point in time with that enabled.