remove any own coding from E1KNA1H, just do the mapping for the first occurance
then go to the __END_OF_RECORD__ of E1KNA1H and add this coding after the transfer record statement
E1KNA1H-TDID = 'xxx1'.
transfer_this_record 'E1KNA1H'.
E1KNA1L-TDLINE = MYTXTFILE-TDLINE1.
transfer_record.
E1KNA1H-TDID = 'xxx2'.
transfer_this_record 'E1KNA1H'.
E1KNA1L-TDLINE = MYTXTFILE-TDLINE2.
transfer_record.
E1KNA1H-TDID = 'xxx3'.
transfer_this_record 'E1KNA1H'.
E1KNA1L-TDLINE = MYTXTFILE-TDLINE3.
transfer_record.
this means you had just submitted a record for the first text header and a record for the first line.
after this you need to submit another text header with the second text ID follow by the line for the second text ID, then again the text header for next ID etc etc.