Hi Sean, thanks for posting and I will be happy to help!
Thanks for the description of the issue you are seeing. I have not witnessed this before when using our docking station and I will be happy to help. When you have a moment, would you be able to let us know the model of the Plugable dock that you are using? You should be able to find the model noted on a sticker on the bottom of the dock.
Just to clarify, when you open Display Settings, the scaling bar to Change the size of text, apps and other items is grayed out and cannot be adjusted? While docked and with the monitor connected, are you able to click “Detect” within Display Settings and see if the scaling bar is then no longer gray?
Pending those results, an alternative method to adjust the text sizes within Windows can be to change the font sizes for specific portions of windows/icons. This guide --> https://www.tenforums.com/tutorials/1… illustrates adjusting these font settings and mention it in case it could be useful for you as a workaround.
Please let us know those additional details and results from those tests at your convenience and we will go from there.