Zombies game has a massive pause before starting and sometimes fails to start

[TheMiniBar]

When playing with 10+ players we're finding a massive pause of 20 to 40 seconds after instructions are announced, before the game starts. Sometimes we end up having to reboot after 60 seconds as it feels like it'll never start.

We noticed this 18 months+ ago, but the issue remains in fresh builds.

Werewolfs as a comparable game starts promptly every time.

Let me know if there's any log files or tests we can do to help solve this.

[TheMiniBar]

Tested today with 21 controllers on a fresh install. Instructions are read, and then there is a 31 second delay before the game starts. Think in the past I've decided the game had crashed and have rebooted and then that has perhaps upset the zombie game more until we reimage the SD card.
Playing again today outdoors later so may have more of an update later.