I would wait. Certainly not stop payment on the check. IRS is slow now because of covid, and closing of that address is a further complicating factor. It’s highly unlikely the IRS has lost it or it has fallen into the wrong hands.
Chances are the check will be cashed within the next few weeks. If you must file your return before the situation is clarified, claim the payment. You met your obligation by sending the check. The delay in cashing it isn’t your fault.