On the main Mac, I added the secondary Mac user's name and password just like I would do if it were two Win 10 computers in a workgroup. I do this exact setup flawlessly at home with Windows for my wife and I she works in the file and then closes QB, then I access it, then I get out and give her access again.
This is a setup where only one user will be in QuickBooks at a time it's not a multi-user setup with both users accessing the files simultaneously. Everything was fine until they wanted to have a second Mac be able to access the three QB database files on the primary Mac a week ago. I rarely work on Mac networks, but one of my clients bought out his cousin's office that uses Macs, and I got them set up on QuickBooks Desktop for Mac 2020 back in January 2020.
