I appreciate you sharing the detailed steps you've taken to restore your company file. But I'd recommend contacting our Customer Care Support since you're still unable to restore it,
This way, they'll be able to pull up and look into your account in a secure environment to investigate further why your unable to restore your company file. And will also share the necessary steps to restore it successfully.
To contact our QuickBooks Desktop for Mac dedicated support, here's how:
In addition, you can read this article to learn more about contacting our support: Contact QuickBooks Desktop Support.
As always, you can visit our Help Articles page for QuickBooks Desktop for Mac if in case you need to learn some "How do I" steps.
It'll be always my pleasure to help if you have any other questions. I'll be keeping an eye for your response.