I assume you did not use a method where you got proof of delivery so there is no way to tell if the IRS got your return. if you call they will not have any better info if the return hasn't been entered into their computer system. at the end of February 2021, it had over 7 million returns it hasn't processed. the IRS prefers that duplicate returns not be filed. it's your decision if you go ahead and send in a second copy. if you do you should use a method where you get proof of delivery.
