chore: Update allow on submit for Sales Invoice fields

erpnext/public/js/controllers/accounts.js

@@ -143,6 +143,12 @@ var get_payment_mode_account = function(frm, mode_of_payment, callback) {
 
 cur_frm.cscript.account_head = function(doc, cdt, cdn) {
 	var d = locals[cdt][cdn];
+
+	if (doc.docstatus == 1) {
+		// Should not trigger any changes on change post submit
+		return;
+	}
+
 	if(!d.charge_type && d.account_head){
 		frappe.msgprint(__("Please select Charge Type first"));
 		frappe.model.set_value(cdt, cdn, "account_head", "");