This sounds potentially similar to my issue here: https://developer.apple.com/forums/thread/737019 I was able to resolve by adding the intermediate certificate to the root user's login keychain (despite the signing identity + intermediate certificates being present on the non root user's login keychain, which was also the user executing jobs for github actions in our case).

This behavior sounds similar to the behavior I encountered here: https://developer.apple.com/forums/thread/737019 Have you tried adding the intermediate certificate (as described in eskimo's post) to the root user's keychain on the EC2 instance? Intermediate WWDR certificates can be downloaded here and would need to be whichever is specified in your development certificate (in my case it was Worldwide Developer Relations - G3)