Excel Add Sheet + Button inputting old data

Good day,

The other day, i tried to add a new tab at the bottom of my workbook by utilizing the + button at the bottom. This created a new tab (Sheet 2) but also inserted five additional tabs between sheet 1 and sheet 2 that seems to be data from another workbook. I am not sure how this data is being pulled into the new sheet function. This also happens if I select New Sheet by any other method. I have tried Quick Repair, as well as uninstalling and installing O365. I cannot seem to find anything about this online. It seems to be cached somewhere unknown to me.  Any advice would be appreciated. Thank you.