Upgraded to 12.0.1 from Catalina 10.15.7 on a 2020 Intel Macbook Pro 13 16GB, USB hubs aren't working, including my Lenovo thunderbolt 3 dock. Since I rolled back to Catalina, I'm getting frequent USB drive disconnects and USB devices playing up more often. I suspect some firmware was updated also, and I still have something from that Monterey upgrade. The fact that this thread is 5 months old shows how piss poor Apple can be. Imagine shipping a major version operating system with broken USB support, despite knowing about the problem for MONTHS. It's USB. USB is broken. Why is this not being urgently fixed I do not understand. My machine is less than one year old.

I installed 12.0.1 and had loads of USB devices fail and so rolled back to Catalina. While it looks like 12.1 solves the problem for many people, I think I will delay upgrading until 12.2 or 12.3 because very clearly this major version is full of bugs.

I actually can't quite believe Apple is shipping this s***. Broken USB? Is it 1995?

I finally pushed the button on 12.1, and it appears to have solved my USB issues. I'm just hoping I can avoid the memory leaks that I've heard about

I've spent quite a while trying to figure out what was breaking my streams with red herring dropped network frames. The major stream platforms do not like variable bitrates, and according to people in OBS support (supported by various anecdotes in OBS' forum) the Apple Hardware Encoder will only work in ABR mode, not CBR. This basically means you that using the Apple 264 Hardware Encoder in OBS (29.0.2 at time of writing) is not suitable for purposes of live streaming on Intel-based macs. [CBR for Apple H264 Hardware encoder was merged in OBS 28 for Apple Silicon]https://github.com/obsproject/obs-studio/pull/6668), but it seems there is no solution for Intel-based macs. The support people in the OBS discord told me this has never worked properly, and probably wont be fixed for Intel macs.