I agree with @Scobie's settings for communication protocol options with CCA. If still no sound:
I have worked through the suggestions on the list, and there was a mention of Whitebear DMRA.
This sees and connects to devices (CCA and Google Nest Mini speaker) but again no sound is played.
I may be missing a trick with Whitebear as I'm not 100 sure of exactly how to use it though!
Whitebear's GUI is a little quirky. WB can play an inspiring short musical segment, and can also test a long list of audio formats in which case it plays short tones. To do the former:
After startup and presumed detection of your renderers, it may still be necessary to go to upper right corner and check "Use Windows Discovery", then "Select a Media Renderer" which initiates another round of discovery. Select a renderer from the popup discovery window and it should then display the screen shown below and, hopefully, start playing the inspirational musical segment. If desired, you can run additional tests, but should not be necessary. Note that all this works whether or not MC Server and MC are running; of course BubbleUPnP must be running properly to "create" the DLNA renderers.
If WB plays sound, but MC only plays brief connection beeps, it may mean the renderer and MC/Bubble cannot agree on an audio format. Check MC Options > Media Network > Add or Configure DLNA Servers > Audio and try settings shown in picture below (they work reliably for me; PCM 24-bit also works).