Excel 365 storing date as serial number

[April_Kingston]

Hello

I'm using an Excel Ghant Chart template from Excel - I've added a line to add in mmm-yy and it displays as the 5 digit serial number.  The cell is formatted as a Custom mmm-yy, but still displays as the 5 digit number.  When I click on the cell the formula bar shows the date but the cell doesn't.

I'm wondering if it's locked as it is a 'standard' template.  I can see a lot of Naming conventions have been applied throughout.  Does anyone know what the fix may be?

Thanks in advance

April

[#2]

@April_Kingston Would help if you could specify which template exactly. There are quite a few out there to choose from.

And you mention "I've added a line.....". I assume you mean you inserted a row. If so, where? Perhaps best to save your file to OneDrive (or similar) and share link that gives access to it here.