ATEM + Firmware 8.6 causes unexpected disconnects

I developed a macOS app with firmware 8.5.3 and the 8.5.3 SDK that mostly just does transitions, calling mixEffectBlock->performAutoTransition().

With the latest 8.6 firmware and SDK, my app works for a couple minutes, then all of a sudden every SDK function returns F_FAIL. I have to kill my app, relaunch, and then it works again for a couple minutes.

I kick myself for updating the software, but regardless I'm stuck with an app that no longer works as expected and will take an indeterminate amount of time to debug what's changed.

Is there a way to downgrade back to 8.5.3? Is that installer available anywhere?

I received an email from developer support, it looks like they've been able to reproduce the issue with the 8.6 SDK. A ticket has been filed and they're working on it, so yay!