Why are there multiple entries after I press the “Convert” action button?

If you get multiple entries after pressing the convert record action button, it's because you map a subtable field to a regular field. For example,

The above setting means you want to create entries in the "Product Invoice" sheet with the "Remarks" value from each subtable row. Hence, if you have three subtable rows in the "Sales Order" entry, the system will convert it into three separate entries in the "Product Invoice" sheet by pressing the action button.

To fix this issue, please add a “Remarks” subtable field on the "Product Invoice" sheet and update the field mapping of the action button: