Elitebook 840 G7 Dock compatibility

[Ixoni]

My work sent me an Elitebook 840 G7 with an Elite Thunderbolt 3 Dock. First question, the compatibility lists I have seen for the dock is only a few laptops and does not include the 840.  Is this for real? Does not make sense HP would make a dock for only six laptops. So far it works except I can only get one external monitor to work. Strangely even though the second monitor does not connect, the Windows 10 display settings at times recognize a third monitor. So am I screwed because the 840 is not on the compatibility list for the dock? Or can you help me get dual external Elite Display monitors to work? Thank you!

[banhien]

@Ixoni 

The dock shows some compatible products

            https://support.hp.com/au-en/document/c04959218

I know for sure the HP USB-C Gen 5 dock is compatible with

HP Elite x2 1012 G2, G4
HP Elite x2 1013 G1, G3, G4
HP EliteBook Folio G1
HP Elite Dragonfly
HP EliteBook 1030 G4
HP EliteBook x360 1030 G2, G3, G4, G7
HP EliteBook x360 1040 G4, G5, G6, G7
HP EliteBook 1050 G1
HP EliteBook 800 series G5, G6, G7
HP EliteBook 800 HC series G5, G6
HP EliteBook 840r G4
HP EliteBook 700 series G5, G6
HP ProBook 600 series G4, G5, G7
HP ProBook 400 series G5, G6, G7, G8
HP Probook x360 435 G7
HP ProBook x360 440 G1
HP Pro x2 612 G2
HP ZBook x2 G4
HP ZBook Firefly 14 G7
HP ZBook Firefly 15 G8
HP ZBook 14u/15u G5
HP ZBook 15/17 G5*
HP ZBook Power G7
HP ZBook Fury 15/17 G7*
HP ZBook Create G7*
HP ZBook Studio G7*
HP ZBook Studio x360 G5*
HP ZHAN 66 Pro 13/14/15 G2
HP ZHAN 66 Pro 14 G4
HP ZHAN 66 Pro 14/A14/15 G3
HP ZHAN 66 AMD Pro 14 G3

It is in front of me right now.

Regards.