This is the failure of group calls in macOS
Although it took Apple more time than desired, finally from macOS Mojave and its equivalents on iOS, it is possible to make calls with up to 32 people via FaceTime. The proper functioning of this usually always depends on the internet connection of the participants, but as a general rule it did not usually bring problems (apart from a fatal security problem reported in 2019 and for which Apple had to apologize publicly).
However, as Zac Hall relates in his post and as we have been able to verify ourselves, group video calls pass normally until, suddenly, Mac freezes and there is no possibility of making it functional again. Only forcing shutdown by button it is possible to make the equipment disconnect and start again normally.
And although it seems that this failure has become apparent in computers with version 12.0.1 of macOS, it seems that could also be present in macOS Big Sur. So at least some of the readers of 9to5Mac stand out, as well as in other consulted forums. The exact origin of the problem is unknown at this time, but regardless, it is clear that it is a serious problem for those who usually make this type of video call. It should be noted that the failure is also independent of the chip architecture, being reported both in computers with Intel processors and in Apple’s ARMs (M1, M1 Pro and M1 Max).
Solution in sight with macOS 12.1?
As we already indicated, only forcing the shutdown with the button is now the solution to this failure. We do not know if your arrangement has much or little difficulty, since not knowing its origin is difficult to make forecasts. However, it is more than likely that a complete system update will be needed to solve it, pointing everything to the next update of the system that will be macOS 12.1.
This version is currently in beta and, although it is not ruled out that a previous version may be released if a major security flaw is reported, it seems to be the closest. Except for surprise, it will be in the first fortnight of December When it comes out of this bug, it is expected that it will be solved. At the moment we have not been able to confirm if it is fixed in the betas, but in view of the fact that it was a little known bug, it is likely that Apple has not yet investigated it. We hope that, once made public, they will be able to find the origin and can be solved in this aforementioned version.