Hi,

If your product's barcode is generated automatically, check to see that it is functioning properly.
Then check the barcode of the corresponding product while scanning the barcode.

Let's say there is a field for scanning the barcode when the product moves, in that case you can use the following code:

scan_barcode = fields.Char(
        string="scan product",
        help="scan barcode of product here")

    @api.onchange('scan_barcode')
    def onchange_scan_barcode(self):
        """checking barcode with the corresponding product"""
        order_product = self.env['product.product'].search(
            [('barcode', '=', self.scan_barcode)])
        lst=[]
        if order_product:
            for rec in self.move_ids:
                lst.append(rec.product_id.id)
            for rec in self.move_ids:
                if order_product.id in lst:
                    if order_product.id == rec.product_id.id:
                        po= self.env['purchase.order'].search([('name','=',self.origin)])
                        for product in po.order_line:
                            if product.product_id.id == rec.product_id.id:
                                rec.scanned_count += 1
                                rec.product_uom_qty += 1
                                rec.product_barcode=self.scan_barcode
                                self.scan_barcode = 0
                                break
                else:
                    vals = {
                            'name': order_product.name,
                            'product_id': order_product.id,
                            'reference': rec.reference,
                            'product_uom_qty': 1,
                            'product_barcode':self.scan_barcode,
                            'product_uom': order_product.uom_id.id,
                            'picking_type_id': rec.picking_type_id.id,
                            'origin': rec.origin,
                            'scanned_count':1,
                            'location_id': rec.location_id,
                            'location_dest_id':rec.location_dest_id
                        }
                    self.write({
                        'move_ids': [(0, 0, vals),]
                    })
                    lst.append(order_product.id)
                    break
        else:
            raise ValidationError(_('Sorry there is no product with such barcode'))
        self.scan_barcode = 0

Regards