XPS 17 Not Supporting 2 External Monitors at Full Resolution

Hi all,

I have an XPS 17 9700 with two Dell U2518D monitors connected via display port (max resolution 2560 x 1440 at 60 Hz).  I just switched the dock from the D6000 (because it doesn't allow full charging with USB-C) to the WD19S.  When I used the D6000, I could connect at the full resolution on both monitors.  But now that I am using the WD19S, the laptop charges via USB-C, but only one monitor connects at the max resolution and the other connects at only 1920 x 1080 as the highest available resolution.

Does anyone know how to make the WD19S connect both monitors at max resolution?  If not, is there another dock I should be using that allows for both UCB-C charging on the XPS 17 and support for two monitors @ 2560 x 1440 resolution?

Thanks in advance for any advice!