My Plugable UD-3900 dock flickers (turns off and then on) randomly when attached to my HDMI monitor.

I run a setup in which two monitors are powered by my Surface Pro 3 through the Plugable UD-3900 docking station, which I bought a year and a half ago. One monitor is connected via HDMI, and the other by DVI. For the past few months, whenever my HDMI monitor is connected, the Plugable hub will randomly seem to turn off or flicker, which has the effect of disconnecting both monitors for three or four seconds (this happens maybe every fifteen minutes). I find that when only my DVI monitor is attached, I have no problem, but when the HDMI alone is attached, or both the HDMI and DVI monitors are attached, I have this problem.

Surface Pro 3 i5
Asus VX238H-W (HDMI monitor)
ViewSonic VX2450vm-LED (DVI monitor)

Other attachments:
• USB dongle for Microsoft wireless keyboard and mouse.
• Seagate USB hard drive.
• Headphone jack.

I will follow up with a direct message asking for logs.