Why is shared document from one drive asking others to sign in?

I have a spreadsheet on one drive that I need others to be able to access and edit certain cells.

I have selected that anyone with the link can edit, but when embedding, the embedding link if followed asks for a sign in.

I don't want to share the whole workbook (which actually shares fine), just the selected range and i dont want others to have to sign in.

Am i missing something simple?