I don't think you are understanding the issue.  I've encountered similar QB errors over the past months .. and am facing the same again. 

If I pick a standard QB report (for example this quarter's balance sheet with show previous period selected) and attempt to export to excel I get an error "Excel allows 256 columns in a worksheet.  This report has 8 columns (6 row title columns + 2 data columns)  Use "Customize" to change the number of columns in this report.  In the past this error would occur on some reports but not all ... today, after accepting the latest upgrade it is with all reports.

Again, this is a canned QB report.  

Environment QB Enterprise 20.0

Office 365 MSO (16.0.14026.20202) 32 bit