If your detail style view is not attached to a row, then there is no column value to change since the screen is not currently viewing a specific row. This happens when you have no rows of data in your sheet, but can also happen if you have a filter set on the tab or if you have row owners enabled and the email you are using doesn’t have a row in the sheet. Be sure to check if you have row owners enabled or if you have a filter set on your tab.