Plantronics devices in Windows 10 only do not receive sound from our application

Hello everyone, we are expecting an issue with an application we are developing, description of which follows. Devices we know are affected: Savi 410, Savi 420, Savi 440, Savi 445, Savi 740 (Those are devices we had handy and could test it with, we expect other devices are affected). Devices we know are not affected: Blackwire C520, Voyager Focus UC B825.   The Application: Our application runs on Electron (which DOES exhibit the same issue), which runs on Google Chrome (which does NOT exhibit the same issue, perhaps due to whitelisting?).      Issue description: When using application with one of the Plantronics devices mentioned above on Windows 10, no sound can be heard. The audio input (microphone) works fine, therefore the issue only applies to audio output. The application does recognize the device (as in we are able to select it as audio output).  Has anyone ever experienced similar issues? If so, what are some of the ways in which we could fix this? Thank you very much in advance! Zuzana Chlupackova