This is a known issue for several months now. I have been testing Sonoma on a number of Mac's with different configurations and when you open up any QB Mac version under Sonoma, it spikes the processor to 100% usage and then crashes and requires a force quit.
The development teams are aware of the issue, however I have not heard any feedback on when this will be resolved. (I'm in the same boat and had to use an older 'vintage' Mac that is running an older OS to get back up and running with QB.)
Please be patient - I'm sure that patches will be coming soon!
