I have an Excel located in SharePoint Online Library. I tried using Intersect to detect any change or update in Column A, Column B will be updated to the month value of the change or update made in respective Column A.
It works well in Microsoft Excel Desktop App, but if I open the Excel in Web browser, the function not firing.
Check the function and/or formula/VBA. Things like "color" for cells are not available in the Online Excel, nor will VBA and macros work.