If we have an issued invoice under the reverse charge mechanism and one of the line items is an automatically created rounding item, this item inherits the VAT lines and control statement lines from the document header, and this setting cannot be changed.
The solution is to open the document, go to the Rounding Method tab, and set the value in the Total (digits) field to Do not round. Then, in the line items section of the document, use the Add button to add a new rounding item with the desired rounding value. On the Posting/Details tab, uncheck the "Copy from document" field for the VAT lines and the control statement line, and set the values to "No impact". A rounding item created this way will not be included in the VAT return or the control statement.