Hi Antonio,
If I got your question, you expect the payment's posting date to be the same as the value dates of the bank statement items.
If so, as far as I know, the expected behaviour is the payment to have the posting date of the bank statement. In case of payments initiated by Bank Statements, the source document for these payments are the bank statement and this is the reference document with which system generates the payments. So here the posting date of the bank statement is considered as the posting date of the individual payment items.
I hope this helps.
Best Regards,
Alexandre.