PowerExpand 12-in-one HDMI port not working, tried two different Windows laptops

Just bought this. Every other port is working just fine – all USB ports including Power Delivery, audio, wired Ethernet. Have tried two different laptops. Same HDMI cable works fine either plugged directly into laptop or plugged into a different USB hub (wavlink) with HDMI. Also tried 2 other HDMI cables that work well in other contexts.

Device Manager in Windows does not show a Display Adapter corresponding to the HDMI port.
There is one “Unknown Device” in Device Manager.
Device instance path = ROOT\VMS_VSMP\0001
I can get other properties from Device Manager but I don’t see any useful ones.

I’ve looked over the other PowerExpand/HDMI threads on the forum and haven’t found an answer. Any ideas?