It's not cache related, so please stop with that advice. Since the "new" templates for invoices this "pay invoice" button has been popping back into invoices every time even when turned off. Make it an option to completely turn off this feature company wide, that is the solution. It's so infuriating to have to spend double the time on an invoice to try and remove this button I am seriously considering moving to different software to spare me the frustration.