Hey there!
i have no sound at all while playing with my MacBook Pro (Retina, 15-inch, Mid 2015) via macOS 10.14.6 (18G3020). I double checked if the right sound output is beeing selected while playing. I never had/have this problem in other games so far.
++ Update ++: I just installed macOS Catalina 10.15.4 (19E287) but the problem isnt solved unfortunatly …
Best wishes,
Btw.: Im playing via a egpu Razor Core + RX580 on pretty high settings @ 2880 x 1800 and it seems to run pretty smooth. I also tested the game without the egpu – also with no sound.