I had this same problem but for different reason. This is what I did.
Go to App store>today screen. Upper right corner, tap on your profile photo. This will take you to your Account screen. Tap on you Apple ID at the top. You will get a pop-up asking you to sign in. Do that whatever way you normally would (password, fingerprint etc). You should now be in Account Settings screen. Scroll down to "Hidden Purchases". Tap on that. Here you should find your missing apps.
If you can't find it there, go back one page to Account Settings. Tap on Purchase History and look for it in there. You can go back several years to search. All apps, paid and free will be listed there. Contact Apple support and they will restore your purchase. Good luck. Hope this helps.