Audio/Video Devices are no longer accessible via Media Player on Mac.
User info: "We think it is connected to camera and microphone privacy. We have got a crash trying to access to camera from custom plugin on macOs 10.14 and 10.15 While it works well on mac 10.13 and windows"
Result: No devices listed on MacOS
There's no existing public thread on this issue, so head over to Questions & Answers just mention UE-87136 in the post.