The phone was on silent. Turned it off silent mode and the game audio works just fine now.
It’s a little deceptive cause it tells you the volume is up but it still plays nothing and you’d never suspect Silent Mode being the culprit.
I got the iphone X is there’s a little tab you have to manually switch for silent mode to turn off.
“From the top left edge of the device, flip the Ringer switch to turn Silent Mode on (sound is off, switch is in red position) or off . The silent mode/ringer notification briefly appears on screen.”
This also was my problem, the PHYSICAL button on the phone controls this. There must be something we can do to get around it though. Anyone have suggestions? Other apps can clearly play even when the phone is on silent, just not my app.