Customer.GroupCode not set by method directive

I have a postprocessing method directive that sets the customer Id of a new customer to “Auto” (that works nicely) and attempts to set the GroupCode to “COD”. This latter part does not work, though clearly the directive executes the step. I tried to set the CustGrupCodeDescription to the description of the GroupCode, nothing works….
If any one has an idea, please share.
Thank you.

Post processing directive doesn’t affect the data on the dB because it happens (post /after) the business logic
What method did you put this in?

I put it in GetNewCustomer. The first part of setting the customer id to “Auto” works fine. It’s just the second part…;

I’d put something like that in pre-processing myself.