I actually have the same problem, for this and other Unity games, but I have a fairly weird workaround to it.

At a guess, the game is detecting a different 'default' audio device than whatever you're actually using. I use the 'Nvidia RTX Voice' program to help gate low-level audio over my microphone, and since it registers itself as an audio device Unity might be trying to play audio through that program, even though it has no actual output. If I disable it and relaunch the game, though, sound suddenly starts working flawlessly.

Odd thing is, this only works if I have the program active before I launch the game; if I launch with the program already turned off, it won't play audio even after relaunching. I have to turn it on, launch the game, turn it off, then relaunch the game to get any kind of audio.