Hello ,
I want to send and display a customer field in sale order line
Currently my field is correctly set in the sale order line by onchange but when I click on the save button of the order line the field becomes empty.
Here is my code below :

class Sale_order_line(models.Model):
_name = 'sale.order.line'
_inherit = 'sale.order.line'

myfield= fields.Char("taille")

@api.onchange('myfield') 
def onchange_taille(self): 
​

if self.order_partner_id.my_customerfield: 
values = {
'myfield': self.order_partner_id.my_customerfield and self.order_partner_id.my_customerfield or False, 
}
self.update(values)

Can anyone help me please?

Thank you