Impacted versions:
* 11.0

Steps to reproduce:
* Create company A
* Create company B
* Admin user with both companies but currently in company B
* Create Demo user only with company B
* Create fiscal position A to company A
* Create fiscal position B to company B
* Create vendor with fiscal position A with company A and the same vendor with fiscal position B in company B
* Create product and add the vendor created before
* Set like **Create a draft purchase order**
* Logging with Demo user
* Create sale order with one sale order line with route **make to order**
* Validate sale order

Current behavior:
The purchase order created by sale order has the fiscal position **company A**

Expected behavior:
The purchase order must have fiscal position **company B**
for order in self:
            amount_untaxed = amount_tax = 0.0
            for line in order.order_line:
                amount_untaxed += line.price_subtotal
                
                if order.company_id.tax_calculation_rounding_method == 'round_globally':
                    taxes = line.taxes_id.compute_all(line.price_unit, line.order_id.currency_id, line.product_qty, product=line.product_id, partner=line.order_id.partner_id)
                    amount_tax += sum(t.get('amount', 0.0) for t in taxes.get('taxes', []))
                else:
                    amount_tax += line.price_tax
            order.update({
                'amount_untaxed': order.currency_id.round(amount_untaxed),
                'amount_tax': order.currency_id.round(amount_tax),
                'amount_total': amount_untaxed + amount_tax,
            })
    @api.depends('order_line.date_planned')
    def _compute_date_planned(self):