Envy x360 dual monitor resolution issue

[Hawksnest2]

When I connect 2 monitors to my Envy x360... the first monitor allows resolution of 2560 x 1080... However, the second monitor only allows a maximum of 1920 x 1080

Laptop: HP Envy x360 Convertible 15-eu1xxx (2 in 1)
Monitors: LG 34WK650  (connected via Display port)

Dell Docking station: WD19TB

 -2  display ports (1 to each monitor)

Docking station connected to laptop via usb-C

Monitors are identical

either monitor connected by itself will provide the 2560 x 1080 resolution

either display port on docking station when connected by itself provides the 2560 x 1080 resolution

if only:

Port 1 - monitor 1 - (2560 x 1080) 

or 

Port 1 - monitor 2 - (2560 x 1080)

or

Port 2 - monitor 1 - (2560 x 1080) 

or 

Port 2 - monitor 2 - (2560 x 1080)

whichever port/monitor added second will only be 1920x1080

for example:

Port 1 - monitor 1 - (2560 x 1080)  (connected 1st)

Port 2 - monitor 2 - (1920 x 1080)

or 

Port 2 - monitor 2 - (2560 x 1080)  (connected 1st)

Port 1 - monitor 1 - (1920 x 1080)

dual displays worked just fine with these monitors/cables for my Dell laptop...   (granted I know I'm using a dell docking station)... but that doesn't seem to be the issue as either port / monitor works fine individually... 

I just bought this HP Envy x360.... so I can still take it back if this won't work...  

Thanx for any help...

[banhien · Accepted solution]

@Hawksnest2 

That is the problem with your Dell dock and your HP Envy, they are NOT compatible. What is your Envy ? I can't find a specs of an HP Envy 15-eu1xxx machine BUT I believe it only has USB type C port (which is NOT a Thunderbolt™ 3 port) and the Dell dock supports Thunderbolt 3 connection.

Note: Not all USB-C ports are the same.

Regards.