Hey Kevin, that was my original post. The only way I was able to resolve it was by adding a separate powered USB hub w/ethernet (got it from amazon for $15 or so). I now use the plugable dock for the monitors, speakers and microphone, and I use the other USB hub for ethernet, keyboard, mouse, and connecting other USB devices.
I have the plugable dock connected to the USB-C port on my laptop, and the USB hub connected to a ‘regular’ usb3 port on the laptop.
The issue isn’t limited to Plugable devices, I bought another dock from another manufacturer and got the same issue. I believe it’s with the DisplayLink chip. I went through a bunch of troubleshooting with DisplayLink directly, but they were not able to reproduce the issue.
By adding the extra powered USB hub, the keyboard issues are 100% gone. I get a very occasional flicker from the monitors, maybe once every two weeks but all the issues are infinitely better now.
Wish there was a cleaner solution than adding an extra piece of hardware, but after exhaustive tests that’s the only way I found to resolve it.