Why monitor flicks on my ThinkPad Thunderbolt 3 Dock (40AC) Gen1 with MacBook?

macOS has some limitations about multi-screen docking stations on Thunderbold 3 ports

https://unsplash.com/photos/BMnhuwFYr7w

Environment

macOS Big Sur version 11.5

Issue

The monitor “blinks” every couple of seconds.

The MacBook Pro is connected to the ThinkPad Thunderbolt 3 Dock Gen1 (Model No: 40AC — DBB9003L1). The monitor is connected to the dock using the Displayport cable. The monitor(s) are configured as “extended”.

Diagnostic Steps

• Usage with a Windows 10 laptop with the same dock and monitor does not recreate the issue.
• Usage the same HDMI cable as above but connected via the dock, the blinking persists.
• Replacing the cables and the dock itself with the same result.
• Performing a System Management Controller Reset on the Mac according to this article did not improve the situation.
• I tried lowering the resolution (1080p/720p) and refresh rates for the monitor as a test, the behavior did not change.

Resolution

• Use a USB-C -> HDMI adapter with the MacBook Pro…