An SSL error has occurred and a secure connection to the server cannot be made

Error Domain=org.openid.appauth.general Code=-5 "Connection error fetching discovery document my domain/auth/realms/test/.well-known/openid-configuration': An SSL error has occurred and a secure connection to the server cannot be made.." UserInfo={NSLocalizedDescription=Connection error fetching discovery document 'myDomaintest/.well-known/openid-configuration': An SSL error has occurred and a secure connection to the server cannot be made.., NSUnderlyingError=0x600001eb6dc0 {Error Domain=NSURLErrorDomain Code=-1200 "An SSL error has occurred and a secure connection to the server cannot be made." UserInfo={NSLocalizedRecoverySuggestion=Would you like to connect to the server anyway?, _kCFStreamErrorDomainKey=3, NSErrorPeerCertificateChainKey=(

), NSErrorClientCertificateStateKey=0, NSErrorFailingURLKey=myDomain/auth/realms/test/.well-known/openid-configuration, NSErrorFailingURLStringKey=myDomain/auth/realms/test/.well-known/openid-configuration, NSUnderlyingError=0x600001e63d50 {Error Domain=kCFErrorDomainCFNetwork Code=-1200 "(null)" UserInfo={_kCFStreamPropertySSLClientCertificateState=0, kCFStreamPropertySSLPeerTrust=<SecTrustRef: 0x6000021d9220>, _kCFNetworkCFStreamSSLErrorOriginalValue=-9802, _kCFStreamErrorDomainKey=3, _kCFStreamErrorCodeKey=-9802, kCFStreamPropertySSLPeerCertificates=(
""
)}}, _NSURLErrorRelatedURLSessionTaskErrorKey=(
"LocalDataTask .<1>"
), _kCFStreamErrorCodeKey=-9802, _NSURLErrorFailingURLSessionTaskErrorKey=LocalDataTask .<1>, NSURLErrorFailingURLPeerTrustErrorKey=<SecTrustRef: 0x6000021d9220>, NSLocalizedDescription=An SSL error has occurred and a secure connection to the server cannot be made.}}}

Start by examining how the AppAuth-iOS SDK fetches the OpenID Connect discovery document and compare that path with the reported NSURLErrorDomain -1200 and peer-trust details. Reproduce the request against the reported discovery URL; done requires identifying whether the failure is in the SDK or the server certificate/configuration, but the issue names no source file or test.