Excel on Mac Changing Sorting Settings on its own when adding information in next column

Looking to see if there’s a setting that does anything about this extremely annoying issue I have. I do cash application, so I’m often matching payments and have an additional column on the remittance file for the invoice # it applies to. I usually don’t add a header because it’s not needed. Problem is my previously set sorting options include headers, but when I add info in said column it switches to not include headers. Why??? That is a setting that should not change unless I expressly tell it to. Is there any kind of option to change this? Or just another one of those things Excel does on its own that you can’t stop?