Xavier wrote: Hi,
ps: after a second attempt it seems that if you select a customer, then another one it is not working as expected. So in this case you have to close the cart edition page (go back on the listing) and open again the cart page and set the customer.
if I understand this issue correctly, it is the same issue I had in the past.
When you select customer for the cart, there is a race condition.
Click on the button fire 2 requests: submit form and parent window reload
<button onclick="hikashop.submitform('customer_save', 'hikashop_form'); window.parent.location.reload();" >..</button>
if form submit is faster, everything is ok. Otherwise you have to reopen the cart.
In case you saved cart before, parent reload will replay post request and if form submit is faster, then previous customer is saved again.