Experiencing Strange Lag Spikes in WoW - All Troubleshooting Exhausted! (Help!)

I'm reaching out to the community because I'm at a complete loss with a persistent lag issue in World of Warcraft. It's not your typical lag; it manifests as sudden, intense spikes that last anywhere from a few seconds to a full minute. During these spikes, everything freezes – movement, combat, chat – making the game unplayable.