Autofill No Longer Working Xcode Developer or TestFlight Signed Builds?

Regarding the XCode issues, the reason seems to be the same as above for the most part. XCode-signed applications also come from the Apple Worldwide Developer Relations Certification Authority CA and then a personal certificate issued to your Apple ID. These ones may be tricky to support, if at all, as it would allow anyone with an Apple developer account to sign an app pretending to be another in a way that Universal Autofill would accept.

Yeah, I went through a similar thought process about this issue. If it helps, External TestFlight builds DO have to go through an App Store review process by Apple (it's not as intense of a review as the final App Store approval, but they don't really disclose what is and is NOT covered in such a review).

Xcode builds, obviously, do not go through any sort of review process. That said, I'm not sure who you're really protecting by blocking credential fills on Xcode builds. I'm pretty sure Apple already blocks me from just handing those builds over to run on someone else's machine. Thus, for someone to actually be harmed by a malicious password-harvesting build they'd have to first download Xcode, compile the code, and run that code on their system. Likewise, other developers are NOT allowed to build code using my App ID. This makes such users already on the more tech-savvy side, and unlikely to trust arbitrary codebases with their credentials, and the AutoFill wouldn't automatically pop-up for them anyway (as their compiled app would have a different App ID).

All-in-all, though, I'd be much happier if it at least worked on TestFlight. I can handle the Xcode builds the hard way (with old school copy-and-paste).