Bug macOs build from 2020.3.x OR 2021.3.x and Xcode 13.2.1/4.1 = Burst not enabled

EDIT: I tried a blank project and put it on 2021.3 and STILL no burst when I build for macOS with Xcode project.... seems this is related to Xcode 13.4.1?

2nd EDIT: Installed Xcode 13.2.1 as well and no difference with either 2020 or 2021, including having built the project from my PC.

tl;dr: macOS builds through Xcode are somehow not using Burst

Original:

I suspect this started since I updated to 2020.3.35. Our game is on all Apple platforms and has been for some time now. A little while back I had to update my Unity because of an App Store requirement (or something, I forget already) and the current at the time was 2020.3.35.
I only found out recently that my bursted jobs aren't getting bursted in the Mac build, but it does work fine on iOS and tvOS and in the Editor. I'm not getting any build errors from either Unity or Xcode though. I tried updating Burst from whichever old preview version up to, I think 1.4.0 was there. I've gone up to 1.6.6 and 1.73 and no difference.

In a new test project I made a build without Xcode using the Mono backend and it works great. Once I switched the build to an Xcode project and ran from there, no Burst. I'm running this all on the first M1 MBP (2020), running macOS 12.2 and Xcode 13.4.1, and before that 13.3 which had issues with Burst on tvOS (and iOS? I forget already, so many different versions of everything).

I've tried debug and release builds, Silicon and Rosetta... Is this a known thing? Has anyone already gone through every version of everything to find a working combo? Otherwise I could submit a bug with this empty project.

 

Bug filed, status here, not sure what happened to Fogbugz...
https://unity3d.atlassian.net/servicedesk/customer/portal/2/IN-13811