I should also ask, is your audio coming from the camera or from the 1/8” jack on the ATEM? The camera’s HDMI feed will always be delayed, and you can tweak up to 8 frames of delay in the ATEM itself to compensate.

aha, I would’t trust the computer to be able to bring the two in sync, it’ll be more reliable to run the audio into the ATEM, then you ensure the audio and video are in sync before they reach the computer. (In case it’s not clear, I don’t trust computers for anything realtime)

What didn’t work about running the 2i2 line out into the ATEM Mini? That shouldn’t be a problem.

oh funny, but that shouldn’t matter, run the line outs into the ATEM anyway, or does it not even have a way to pass its input to the line output? I coulda sworn it did but it’s been a few years since I’ve used a Scarlett device

That definitely should work. Did you double check the mic vs line setting in the ATEM config for that input?