We have updated our blog post with more information about the iOS 26.4 change that makes it impossible for custom keyboards to identify the host application. The problem remains in the 26.4 RC, so we urge all affected keyboard developers to report this to Apple asap.

https://keyboardkit.com/blog/2026/03/02/ios-26-4-host-application-bundle-id-bug

iOS 26.4 Host Application Bug

A change has been discovered in the iOS 26.4 betas and RC, that causes the host application bundle ID to become empty. This causes differ...