TBT3-UBZ HDMI ports not working with Macbook Pro

Just got my new TBT3-UDZ from Amazon delivery guy. Cleaned off the desk, re-routed all the wires, and plugged in my two HP Envy 27 external monitors. Plugged the Macbook Pro (13-inch, 2017, Two Thunderbolt 3 ports) into the unit and…nothing. Nada. Zip. The battery indicator indicates the MBP is charging, and there’s a faint blue light on the front of the dock unit, but I’m getting nothing. Nada. Zip.

Both monitors are getting power (orange standby lights are on). When I power-cycle them, I get a message that they aren’t receiving an input signal. But when I open the Displays panel in Settings, it shows all three displays.

Any advice?