Our iOS/iPad app is built with React Native. We use Axios as our HTTP client. Our app has been out on the app store for 2+ years and we've never had issues with reviews. Since iOS 26 came out, our app has been constantly getting rejected because the Apple tester keeps facing network timeout issues when our app makes requests to our API services. Our API stack is already configured to support IPv6 networks, and our regular user base does not run into the issues the Apple tester is seeing. None of our developers nor our internal testers have been able to reproduce the issue the Apple tester is facing.
We've tried a number of things to debug the potential issue:
- Added a ping check on app startup. We used the native fetch present in React Native apps as well as our Axios client (with the default XHR/HTTP adapter). None of the pings make it to our API services.
- Added higher timeouts on app startup to let the Apple tester have more time to reach our services while their simulator device is able to connect. We've read that the environment that Apple testers use can sometimes take longer to establish an initial connection, even though packages like NetInfo from React Native report that they are connected to WiFi as soon as the app starts.
- Switched our Axios client adapter to use the native fetch. We did this since we noticed that Mixpanel, our tracking library, uses the native fetch in their React Native SDK and we've confirmed that requests on their end do make it through when the Apple tester is testing our app.
We're running out of ideas since the issue is pretty obscure and we haven't been able to reproduce it yet, not even by following the Apple guide to set up a local IPv6 NAT64 network to be as close to their environment as possible. We've also tried testing the app while connected to VPNs from different locations to no avail.
Like I said before, we noticed that this issues started for the Apple tester with the release of iOS 26, so we're wondering if there are known issues in the community that might relate to what we're experiencing. The most recent finding we've made is that some other developers report new issues with HTTP 3/QUIC on iOS. We've seen recommendations about turning off explicit support for HTTP 3 on our services, which seems to have helped other developers.