Settings for 'original audio' on zoom are missing on desktop linux. As I imagine HN skews towards that OS, I'd encourage you to write to them asking for support (or avoid zoom altogether; but that might be impossible for some).

If you really want that full-duplex audio experience on linux today, disable audio on the call and move everyone to https://cleanfeed.net. This is not an ideal workflow, but it gets you there.

Why other products don't just take audio seriously is a pity.