Title says it all. I upgraded to macOS Sequoia and now when I press Play both my screens blank out then come back on with Unity app moving to the other display, then blank and switch endlessly. If I unplug the extra screen all works normally. Anybody else seen this?
Non Unity related I think.
For me after sleeping my mac, the monitors might swap positions when woken up.
And to fix it i’ve been doing:
- cmd + ctrl + q (lock)
- esc (sleep)
- unplug both extra usb-c monitors
- re-plug them
- wait 3s
- wake the computer
- (my watch lets me in without the password)
50/50 chance of monitors now being swapped back to the correct location 
Thanks for the reply. It works on macOS earlier than Sequoia and I don’t think it’s Unity per-se but something changed in the latest macOS.
To be clear, it’s not randomly swapping, it’s continuously swapping every 3 seconds when in play mode. Shortcut keys don’t work, I have to jiggle the mouse rapidly and click the play button again before 3 seconds otherwise screens go blank and swap again.