Same issue here using Windows 10 and the latest version of Acrobat 2020. This used to work without issue and without having to change security settings or download extra software. The 'Record Audio' function from Comments no longer works as it did before (it seems to record but it does not playback the recording) and it is a major disappointment for many users who rely on this function and is the primary reason why we use Acrobat. The Attach File option works but it is not ideal. I hope a solution is available soon.