Directories not showing up, but found in search

[SteveyDevey]

Problem Description: I'm noticing that some artists are missing when browsing, but not when searching. One of my media folders is a collection of directories of genres of music. Each genre directory is organized as: genre/artist/album/tracks and this works pretty well for my relatively large collection. When browsing the genres, I see large lists of these artist, but I've noticed that not ALL of the directories (artists) show up. And some of them are in an odd order; being shoved to the bottom, and sorted there. Once in a while, artists will ONLY be shown as blocks that look like albums, instead of artists (which subsonic is probably assuming are actually albums). If some of this weirdness is simply because it's not in a artist/album/tracks layout, I can understand. What doesn't make sense is that items are completely missing, but I can use the search to find them, and the breadcrumb trail at the top shows that they exist in the correct directory.

Troubleshooting Steps: can't think of anything to really test
Playback Application and version: Web interface OR android player
Subsonic Version: 5.3 (build 4568) – October 24, 2015 -- but I may try to upgrade to 6.0 beta1 (or spin up another machine) to test
Server Version: jetty-6.1.x, java 1.7.0_91, Linux (115.9 MB / 214.8 MB)
Hardware Platform: VM, running CentOS Linux release 7.2.1511
Java Memory Limit: 750M