Seems this was changed in NAV2017. Many customer like to setup a customer called 'CASH', enter it on a Sales Order and then enter the actual name of the customer in the 'Customer Name' field. In NAV2016 you are free to change the 'Sell-to Customer Name' for this functionality.
I forgot to mention that this causes user experience issues among many of our users who need to refer back to the previous record from which a new record (such as new activities or cases) is being created.
I have the same need at 2 customers. If the vendor/customer does not have a purchaser/sales person, it should not clear the field, when it comes from the user setup.
For crying out loud....
This WAS reported as a bug! #119101821000989
From which I was told this is by design, and that I should raise an idea instead.
Now it's been turned down both places. What should I do from here???