I have a formula that returns as expected
=IF(ISBLANK([unique.invoice]@row), "", JOIN(COLLECT(collect:collect, [Invoice No.]:[Invoice No.], [unique.invoice]@row), CHAR(10)))
but I tried to replicate the formula to join collect another column and its not working
=IF(ISBLANK([unique.invoice]@row), "", JOIN(COLLECT(COLLECTt:COLLECTt, [Invoice No.]:[Invoice No.], [unique.invoice]@row), CHAR(10)))
or
=IF(ISBLANK([unique.invoice]@row), "", JOIN(COLLECT(COLLECTt:COLLECTt, [unique.invoice]@row), CHAR(10)))