Why does my exported excel file from a budget report have some Category headers incorrect

This is long standing bug.  When exporting the Budget report to using Copy to Clipboard or Export to Excel Workbook (.xlsx), Quicken is attempting to normalize the categories for the spreadsheet incorrectly.  It appears, when searching for the category Insurance, the first match alphabetically is Auto:Insurance and, when searching for Vacation, the first match alphabetically is Salary:Vacation.  If you haven't already, I suggest you report the issue to Quicken: select Help > Report a problem...

There are a few ways to work around the issue.  If you don't require the attempt to normalize the categories, I suggest you export a report to Excel compatible file by pressing Ctrl + P, choosing Export to:, and selecting tab-delimited (Excel compatible) text file.  Otherwise, you may use unique category names or manually correct the error.