GROM-USB2P-TOY S/N 844C firmware v91
2005 4Runner Limited JBL RDS
It seems that the GROM-USB2P-TOY will provide ID3 text only for the first 12 playlists. For tracks on playlists 13 and beyond, only playlist number and track number show up.
As a workaround, I just reorganized my USB drives accordingly. Everything else seems to work great.