Flat file drop down menus stuck on ‘Loading’

I’ve tried opening flat files using google sheets and most of the drop down menus won’t get passed the ‘loading’ phase. It’s only the first one, Product Type, that will show a clickable option.

I’ve tried opening them using Numbers on mac as well but the drop down menus don’t even show.

Does anyone know how to fix this or suggest another free programme to open/edit them? Thanks