@Homespun 

I spoke to QB rep earlier today and he confirmed what I had heard a year ago, that QB 2020 for Mac does not work with Sonoma.

QB Desktop 2020 is outdated, By default Intuit Support will say that it does not support Sonoma. But keep in mind, they only read scripts and have no real experience about it. If you want to be sure, it's best to contact Fiat Lux as I mentioned before. They will provide honest reviews and updates. If you decide to purchase a new license, you can also get a cashback.