Hi @iltonysverbel Thank you very much for putting your trust in mimoLive. I’m very sorry to hear about the technical difficulties.
We can rule out the internet connection as the audio and video is transmitted together so they can’t get out of sync at that point. They could get out of sync when YouTube re-encodes the video but that is very rare.
I suspect that the ATEM Mini is causing USB-C to be overloaded due to the work load on the computer.
This can happen for example because the MacBook Pro is getting too hot. You can check this using the Intel Power Gadget as described here: Thermal Throttling - mimoLive - 5
I don’t think the Focusrite Solo is causing this, but to make sure, can you please do a measurement using the built-in webcam and a microphone connected to the Focusrite using this method: AV Sync Meter - mimoLive - 5
Do one measurement right away, then wait 30 min and do another measurement keeping the audio and video running during this time.
Of course I would do this for you, but I don’t have the Focusrite solo.
Yet another thing you can try is change the USB-C ports that you connect the Focusrite and the ATEM to.
Finally, there will be a slight offset between the ATEM and the Focusrite. You can try to send the audio through the ATEM as well or use the Audio delay setting in mimoLive to correct for the offset. In your YouTube video, I can see that the offset is not constant, though, which it should be.
Please let me know if any of this is improving things.