iOS Question Push messages don't get delivered

[jefflynn1974]

I have an app that has been in the App Store for years and has been working fine. Recently, my clients started complaining that push notifications are not delivered only if they have (re)installed the app. I have an old iPhone that I don’t use daily, and it had the app installed several months ago. I ran a quick test, and it worked fine — until I reinstalled the app from the store. From that point on, push notifications stopped arriving. I’m stuck here. I don’t think this is a certificate or provisioning profile issue, since it still works if the app hasn’t been reinstalled for months.