After a break of several months, I have continued work on an iPhone App. Unfortunately, I cannot run it on any real device anymore, while running it in the simulator works fine. Every time, I connect my mac to an iPhone and try to run the app on it, I get a "Build Failed" and 2 issues: the operation couldn't be completed. Unable to log in with account '...my account...'. The login details for account '...my account...' were rejected No signing certificate "iOS Development" found: No "iOS Development" signing certificate matching team ID "..." with a private key was found. The last time (several months ago), I was able to run the app on many different iPhones from family and friends. The only thing that has changed in the meantime is the Version of Xcode (now 13.3) and MacOS of the machine running Xcode (now 12.0.1). My developer account is still active, just in case this matters. Any help is greatly appreciated!