Problem with Zoho Spreadsheet

Hello,

I am working on Zoho spreadsheet as a school project and I have noticed a major flaw which has been occurring repetitively in the past few days. When I add a button into an excel sheet, the button is there. However, when I change sheets and then subsequently return to the previous page, the button is gone. However, when I export to an excel spreadsheet, I am ramped by buttons which are in the Excel File but not online...

What is going on?