Hello Doug,
The dock is a dual HD dock. HD in that context is 1920x1080.
The DL-3900 chip inside, on HDMI, can go up to 2048x1152 @ 60Hz or 2560x1140 @ 50Hz (
https://support.displaylink.com/know...rticles/525038)
Your dock hardware isn't powerful enough to drive this higher resolution.
To drive these two 3440x1440 displays, you need a dock using our 4K chip, DL-6950.
Here are a few products we have tested using our chips. You can select 2 displays and 4K in the drop down to narrow down. Other models exists.
Regards,
Alban