Hello, 

I am writing a code that changes the Fiscal position in the sale order with the following code:

order.write({'fiscal_position_id': fp_id})

This works well, but now the onchange function for Fiscal position is not triggered?
How can I trigger the onchange function for fiscal position automatically?

For now I added the function manually in the code and this works:

order._compute_tax_id()

Is this normal that this function isn't triggered when the field is changed from the code?