[14.0] Can not reset “posted” bank statement to “new” | error “You cannot modify a posted entry of this journal because it is in strict mode”

[E4eqRL0yw0yajQJ433QL]

Suspected module:
om_account_accountant (not sure though; I really am not a programmer)

Summary of issue:
Unexpected error "You cannot modify a posted entry of this journal because it is in strict mode” when

• trying to reconcile a posted bank statement
• or trying to reset a posted bank statement to status "new".

Context
I just upgraded from Odoo13 to Odoo14 and I dó realize that the reconciliation function was moved to odoo enterprise.
However, the cúrrent behaviour of the bank statement reconciliation is (for me) unexpected:

• Technicallly the system does not allow reconciliation until áfter posting the bank statement (the button "reconcile" does only appear áfter posting)
• However when I try to do the reconciliation áfter posting, the system produces the error about strict mode
• Same when I try to reset a posted bank statement to status "new".

The quick and dirty solution was already presented by one of the odoo mates colleagues:
This error is only raised when "Lock Posted Entries with Hash" in the journal is ticked. So when I unticked this box (using pgadmin) the application works as expected: It lets me reconcile and lets me reset to "new".

The question / improvement proposal
Not sure why the application was designed to do this "hash check on the journal". It seems that I am following a regular reconciliation proces which should also be allowed with "hash-protected" journals.

Further reference
I also reported this issue in the odoo help forum