Screen flicker when driving external monitors through dock

[MichaelAmos]

I've been supplied a Zbook 14, a docking station, and two external monitors to perform my daily job functions.  However, with the monitors connected to the dock (using the two display port connectors), I'm getting screen flicker on the upper quadrant of both monitors when in Windows.  Both monitors are brand new.  I've installed all HP updates (including the September BIOS update).  Internal tech support reports they haven't seen this issue.  I have changed out both the laptop and the dock with no real change in symptoms.

Does anyone have any suggestions?

[MichaelAmos]

Some further information.

I'm using locking display port cables, so they're not slipping out or anything.

No flicker on the monitor I was using previously, unfortunately it was display port>DVI.

No flicker on monitor when laptop is undocked and plugged directly in to laptop Display Port.

Issue has gotten a bit worse wherein the displays will occassionally lose connection and re-establish (screen will blank, the display port icon will display, then screen will return).

I'm assuming it's some sort of issue either with the dock or connectivity through the dock, but I'm at a loss as to what the isssue is and I don't want to keep throwing parts at it.