After iOS 17.4, Passkey Autofill stopped working inside ASWebAuthenticationSession.
iOS 17.5 re-enabled users to pick passkeys if they tap "🔑" icon on right bottom of keyboard and opened Safari password manager. However, it still doesn't recommend passkeys on the first view.
Even on the latest iOS 18.0 developer beta, the behaviour is not fixed yet.
Our engineering teams need to investigate this issue, as resolution may involve changes to Apple's software. I'd greatly appreciate it if you could open a bug report, include sample project and sysdiagnose, and post the FB number here once you do. Bug Reporting: How and Why? has tips on creating your bug report.
Rico
WWDR - DTS - Software Engineer