I did notice that when I played the sweep file in MC 25, using the "file->open media file" option, that the audio came out of my tower PC speaker as well as my speakers connected to my DAC.
That shouldn't happen, unless you have two linked Zones in MC, one for the Dynamic DLNA Renderer (your PS Audio PWD II DAC) and one for the PC speakers. This indicates something is very wong.
In the screenshot you posted I can't see a Dynamic Zones for your PS Audio PWD II DAC, just the "Player" Zone, although the whole "Playing Now" section isn't visible.
Connect and turn on your PS Audio PWD II DAC, make sure it appears under Playing Now, then post a screenshot that shows Playing Now and your "Options > Audio" section of MC settings.
Also, if you have more than one DLNA Server, associate the "Audiophile 24-bit DAC" DLNA Server with your "PS Audio PWD II DAC" DLNA Renderer. See the attached image for how to do that, starting with right-clicking the Dynamic DLNA Renderer record showing under Playing Now.
In the image "BubbleUPnP" is the Dynamic DLNA Renderer and "DLNA Amintha" is the DLNA Server.
Also, if you still have the W7 PC with MC21 installed, have a look at the audio setup in there and make sure the W10 machine is set up the same. Not all that much has changed in the basic way MC is set up with a DLNA Renderer.