User Troubleshoots and Reproduces Passkey Exception Issue for ChatGPT on Xiaomi Devices

On October 11, 2026, a user reported encountering an issue where passkey login became unresponsive when attempting to log into ChatGPT on a Xiaomi device, affecting both web and app login portals without being resolved by restarts or system updates. Through troubleshooting, the user traced the root cause to a null pointer exception in Xiaomi's FIDO component. A read-only analysis indicated that unknown transports values are converted to null and subsequently dereferenced directly, while Chrome source code populates six methods by default when connection hints are absent, with smart-card lacking mapping in the older component. The verified environment included Xiaomi 14 running Android 16, HyperOS OS3.0.306/307, Chrome 154.0.8037.126, and Xiaomi Password Manager 1.0.18. Although the author formulated a root cause model supported by multiple pieces of evidence, they have not yet directly captured the Android service entry point payload or conducted a pre- and post-Chrome upgrade comparison. Currently, in controlled experiments, restricting the connection hints of existing candidate credentials to internal successfully restored the same passkey across both web and app interfaces.