Hi there, @rbrouwer.
I can share some details about the protected mode file in your Excel.
Protected View is enabled by default, and files that are located in potentially unsafe locations are opened in Protected View. You can temporarily disable the Protected View, then open the workbook again.
If this doesn't work, I'd suggest reaching out to the Microsoft Support Team to check further why you're not able to open the file in Protected View.
For more information about Protected View, go to the following Microsoft website: What is Protected View?
I've added this article for your future task whenever you need to personalize your reports: Customize reports in QuickBooks Online. This contains a sub-article about the common custom report.
Please don't hesitate to tag my name in the comment section below if you have other concerns or questions. I'm ready to back you up. Take care.
