BACKGROUND: Just upgraded my plugable ucb-c docking station to the UD-ULTC4K version to be able to have 3 external monitors at 4k resolution. Everything appears to be working fine except DisplayPort monitors max resolution is 2048 x 1152.
Laptop is a Hewlett-Packard Spectre X360 Convertible model 15-DF0013DX running the latest release of Windows 10 Pro. All drivers are updated to latest stable version.
Monitors are a Samsung U28E590 on the 4k port via HDMI cable and two Samsung LU28R55 on the DisplayPorts connected via AmazonBasics DisplayPort to HDMI cables. All three monitors are capable of 3840 x 2160 and display in that resolution when connected to the 4K HDMI port.
GOAL: Would like 3840 x 2160 resolution on the DisplayPort monitors. Recommendations?