Getting error : "Connection error making token request to "<hostname>/connect/token": The network connection was lost..." on iOS 13, 12,11.

We are facing a issue in device in iOS 13, 12 and also in 11.
Here is the log.

Printing description of tokenError:
Error Domain=org.openid.appauth.general Code=-5 "Connection error making token request to 'https://.com/c2a48310-9715-3beb-895e-000000000000/login/token': The network connection was lost.." UserInfo={NSLocalizedDescription=Connection error making token request to 'https://.com/c2a48310-9715-3beb-895e-000000000000/login/token': The network connection was lost.., NSUnderlyingError=0x283b8a460 {Error Domain=NSURLErrorDomain Code=-1005 "The network connection was lost." UserInfo={NSUnderlyingError=0x283b8acd0 {Error Domain=kCFErrorDomainCFNetwork Code=-1005 "(null)" UserInfo={NSErrorPeerAddressKey=<CFData 0x281662710 [0x1c56575e8]>{length = 16, capacity = 16, bytes = 0x100201bb0d23e3560000000000000000}, _kCFStreamErrorCodeKey=53, _kCFStreamErrorDomainKey=1}}, NSErrorFailingURLStringKey=https://com/c2a48310-9715-3beb-895e-000000000000/login/token, NSErrorFailingURLKey=https://.com/c2a48310-9715-3beb-895e-000000000000/login/token, _kCFStreamErrorDomainKey=1, _kCFStreamErrorCodeKey=53, NSLocalizedDescription=The network connection was lost.}}}

No source files or tests are named. Start by reproducing the reported token request failure on iOS 11, 12, and 13, then trace the AppAuth token-request entry point and the underlying NSURLErrorDomain -1005 network error. Done means identifying whether the failure is in the SDK or the provider/network path and documenting or fixing the reproducible cause.