HP G5 Dock teardown by Dan S. Charlton

How do you get the HP USB-C G5 Dock to output dual 4K ?? (Reddit)
enabling High Resolution Mode aka USB-C DP Alt Dock Mode fixed it

HP USB-C Dock G4, G5 – Resolution Issues on External Monitor(s) While Docked (HP)
The external monitor(s) connected to the dock may exhibit reduced resolution. This issue occurs when the maximum USB-C video throughput has been reached with the BIOS default settings.
(the fix) Enable High Resolution mode when connected to a USB-C DP alt mode dock option

HP USB-C Dock G5 (5TW10AA#ABA) vs USB-C Essential Dock G5 (72C71AA#ABA)
In short, the Essential Dock has fewer features.
One of those features may be the lack of WMI support.