Thank you for posting!
Thank you as well for the detail you provided that is much appreciated. A quick note up front, our dock cannot control the behavior of the Microsoft Remote Desktop application on its own.
Further to this, support for multiple monitors within the Microsoft Remote Desktop Client can be tricky due to specific requirements both on the host and server. Adding to the confusion is that Microsoft doesn’t have great documentation in this area. We will of course do our best to help, however we want to set honest expectations up front that we may not be able to provide a solution.
That said, our next step is to get some additional information. First, can you confirm which version of the Microsoft RDP application you are using? I ask because Microsoft has two versions available for Windows 10, an older version called ‘Remote Desktop Connection’ and a newer version in the Microsoft Store called simply ‘Remote Desktop’ (I have attached example screenshots of each to this post to help you identify which is which).
I ask because the older version of the application can support multiple local displays, however to the best of our knowledge the newer version does not (it only supports a single local display).
Old version of client:
New version of client: