diff --git a/models/account_payment.py b/models/account_payment.py
index eecd0ca..b489e01 100644
--- a/models/account_payment.py
+++ b/models/account_payment.py
@@ -11,9 +11,17 @@ class AccountPayment(models.Model):
 
     def action_post(self):
         """
-        Confirmation bypass. Calls standard post with skip flag.
+        Confirmation bypass. Calls standard post with skip flag and FORCES a sync
+        to ensure deductions are applied to the Journal Entry.
         """
-        # Propagate the flag to all internal calls
+        # 1. Force a synchronization of the moves right before posting.
+        # We pass 'amount' and 'deduction_line_ids' to trigger vendor_payment_diff_amount.
+        self_bypass = self.with_context(skip_expense_lock=True)
+        for payment in self_bypass:
+            if payment.state == 'draft':
+                payment._synchronize_to_moves({'amount', 'deduction_line_ids', 'amount_substract'})
+        
+        # 2. Standard confirmation logic with bypass flag for internal writes
         return super(AccountPayment, self.with_context(skip_expense_lock=True)).action_post()
 
     def _synchronize_to_moves(self, changed_fields):
@@ -25,15 +33,14 @@ class AccountPayment(models.Model):
         # SURGICAL JUMPER: If we have the bypass flag, we jump over the hr_expense method.
         if self._context.get('skip_expense_lock'):
             mro = type(self).mro()
-            # Find the class that belongs to the hr_expense module
             hr_expense_class = next((c for c in mro if c.__module__.startswith('odoo.addons.hr_expense')), None)
             if hr_expense_class:
-                # Standard Python jumping syntax: calls the method of the parent of hr_expense_class
                 return super(hr_expense_class, self)._synchronize_to_moves(changed_fields)
         
         return super()._synchronize_to_moves(changed_fields)
 
     def _synchronize_from_moves(self, changed_fields):
+        # Same jumper for synchronization back from moves
         if self._context.get('skip_expense_lock'):
             mro = type(self).mro()
             hr_expense_class = next((c for c in mro if c.__module__.startswith('odoo.addons.hr_expense')), None)
@@ -43,7 +50,7 @@ class AccountPayment(models.Model):
         return super()._synchronize_from_moves(changed_fields)
 
     def write(self, vals):
-        # Propagate bypass flag during writes to avoid checks on draft payments
+        # Propagate bypass flag during writes to avoid locked checks
         if self.expense_sheet_id and self.state == 'draft':
             return super(AccountPayment, self.with_context(skip_expense_lock=True)).write(vals)
         return super().write(vals)