Forms Responses Excel File Corrupt

Greetings,

I believe that Forms has an error when I try to download my responses in an excel file from forms. The file size out of forms is 67MB, but when I trick Forms and force it to only download 5000 rows at a time by inserting ?DownloadFileSize=5000 directly into my HTML after .aspx it saves two files that are around 1.7MB each or 3.64MB when I manually combine them in excel. Any idea what could be causing this issue. It looks to be a Forms Excel generation error. Currently I have the excel spreadsheet linked to sharepoint as it is part of a sharepoint team. If I manually replace this excel spreadsheet in sharepoint will it throw off my forms data?

Thank you!