Hello, Is it possible that the archive of the app differs from the same version of the app but directly in xcode? If yes, why does this happen?

Hello, My app was rejected because testers were unable to sign in to the test account. However, on my test devices, everything works well. Therefore, I think that the problem is that their device is unable to receive a response from a server. I am using HTTP connection and socket connection. I do not know what to do now, on my simulators and test devices everything works fine, but their tests keep failing.