I managed to fix this problem by deleting all signing certificates generated by XCode Cloud and then rebuilding the app in XCode Cloud - no changes to code etc, just a rebuild and resubmit. However, I'm hitting a new issue that I've posted here: https://developer.apple.com/forums/thread/776557 . Basically we have to delete XCode Cloud certs for each build - otherwise it isn't submitted right to App Store.

@go-taras - thank you! Revoking all "(XCode Cloud)" certs fixed it for us!

We are hitting the exact issue - started yesterday morning: Run command: 'xcodebuild -exportArchive -archivePath /Volumes/workspace/tmp/705439ac-65d2-4afe-89bc-d3cdf6310411.xcarchive -exportPath /Volumes/workspace/appstoreexport -exportOptionsPlist /Volumes/workspace/ci/app-store-exportoptions.plist '-DVTPortalRequest.Endpoint=http://172.16.36.64:8089' -DVTProvisioningIsManaged=YES -IDEDistributionLogDirectory=/Volumes/workspace/tmp/app-store-export-archive-logs -DVTSkipCertificateValidityCheck=YES -DVTServicesLogLevel=3' Command exited with non-zero exit-code: 70