Legal enity is greyed out once supplier site is changed in the Ap invoice header

Summary:

Business uses two differen bank accounts in different currencies in supplier site level and there is interbilling invoices are charged from project module(contracts) which uses site1 in USD. Business receives an invoices in EUR for specific service, therefore business needs to use site2 in EUR in the AP invoice that is sourced from Project with site1 in USD. Note that legal entity is also transferred to the invoice from project module. AP Invoice sourced from project module and had not been validated yet and once business changes site1 USD to site2 in EUR, legal entity is overriden to