My WinTV-quadHD only shows up as 2 tuners in Plex

My tuner is a WinTV-quadHD which has 4 tuners. Plex lists it as a supported tuner. But when I see it in Plex it shows it as 2 tuners. What am I doing wrong?

From the Notes section of the Supported DVR Tuners and Antennas page:

WinTV-quadHD: This device will show up as two dual-tuner devices. You can simply add it as two devices to a single Plex DVR to make use of all four tuners.