Audio redirect not working for mic

This problem involves F39, but was also an issue with F38; Plasma; and Windows Server 2019. The Windows Server is properly configured and receives audio from installations other than Fedora/KDE. KDE’s discussion group has not responded to two different posts multiple months apart. So I’m here…

I need to work in a Windows terminal server running Windows Server 2019. One of the necessary workflows is having local audio pickups played on the remote machine, i.e., dictation into a local mic.

When I log in through a browser or PWA from my F39/Plasma machine to Microsoft’s online resources, the local machine’s mic redirects properly. That is, I can dictate from this local machine into that remote app.

When I log in through RDP protocol into the remote Windows machine, the remote machine detects no microphone. I’m using KRDC from the Fedora workstation into the Windows server, tunneled through an OpenVPN Access Server. Regardless of how I configure audio in KRDC’s settings, there’s no remote pickup.

Is this a Fedora issue or a KRDC issue?

Any clues how to fix, if it’s fixable?

(I would like to transition my firm’s workstations to Fedora, but we need the remote Windows server for several workflows, optimally including Teams, Zoom, and dictation on the remote machine.)