I'm seeing a similar issue with just Xcode cloud builds.
Feedback here: FB21343022
For us, changing Xcode version on Xcode cloud doesn't resolve.
To repeat details from the feedback for those at home:
We see the following error on repeated Xcode cloud builds when trying to archive for “iOS App Store”.
Export archive for development distribution
Command exited with non-zero exit-code: 70
The “Archive Build” step is failing with what looks like some internal error.
Xcode Version: 26.1.1 (17B100)
macOS Version : macOS Tahoe 26.1 (25B78)
Attached are the logs, within the relevant part I see this repeated (truncated here for reference and brevity)
2025-12-14T23:42:24.246116551Z error: exportArchive There is a problem with the request entity
2025-12-14T23:42:24.246119266Z
2025-12-14T23:42:24.246121303Z error: exportArchive No signing certificate "iOS Development" found
2025-12-14T23:42:24.246124727Z
2025-12-14T23:42:24.246126906Z error: exportArchive There is a problem with the request entity
2025-12-14T23:42:24.246129486Z
2025-12-14T23:42:24.246131437Z error: exportArchive No signing certificate "iOS Development" found