Disable same customer check between project and sales invoice


I am trying to setup ERP Next for my company and I stumbled upon the following issue:

Some of our Projects are Events organised for Scientific Associations, but all the sales invoices for the events come from 3rd party customers as sponsorships that we then pass on to them.
If i try to make a sales order/invoice for a customer other than the project customer, the system stops me however, and I cannot find a way to disable this check.

Is there a way to bypass this without directly modifying the erp code?

thank you,

May be create a separate custom field in the Project for tracking the customer and leave the standard customer field blank.