Hi Thierno,
Check the logic for the attribute, NbOfTxs (Number of transactions), node ID-N_8432144650, under group header of the Pain.008.001.02 file.
If you could out, how the number of transactions is getting calculated, then you will be able to find the root cause of it.
Check the mapping procedure of the attribute. It is set as Aggregation by default with aggregation type as 2 which means the number of occurrences. That's why may be you are getting 1 as the number of transactions.
Depending on the mapping procedure, you can change the value in the attribute, NbOfTxs (Number of transactions).
Hope it helps
Thanks,
Amlan