A rising retransmission count against an otherwise-stable request count for this specific server is itself a symptom worth investigating independently of whether authentication ultimately succeeds. It points to packet loss or slow responses on the path to this server, which will eventually degrade user-visible login latency even before it starts causing outright failures. For example, a retransmission count that's 20% of the request count for this server would suggest meaningful packet loss on the path to it, even if most logins still eventually succeed.