fix: Reset represents company on disabling internal customer and supplier (#31302)

diff --git a/erpnext/buying/doctype/supplier/supplier.py b/erpnext/buying/doctype/supplier/supplier.py
index 97d0ba0..43152e8 100644
--- a/erpnext/buying/doctype/supplier/supplier.py
+++ b/erpnext/buying/doctype/supplier/supplier.py
@@ -84,6 +84,9 @@
 		self.save()
 
 	def validate_internal_supplier(self):
+		if not self.is_internal_supplier:
+			self.represents_company = ""
+
 		internal_supplier = frappe.db.get_value(
 			"Supplier",
 			{
diff --git a/erpnext/selling/doctype/customer/customer.py b/erpnext/selling/doctype/customer/customer.py
index 8889a5f..35e0b0d 100644
--- a/erpnext/selling/doctype/customer/customer.py
+++ b/erpnext/selling/doctype/customer/customer.py
@@ -141,6 +141,9 @@
 				)
 
 	def validate_internal_customer(self):
+		if not self.is_internal_customer:
+			self.represents_company = ""
+
 		internal_customer = frappe.db.get_value(
 			"Customer",
 			{