Guild Wars 2

I wanted to start this topic to see if Anet is aware of a problem regarding monsters resetting randomly during battle. I have been running into this more and more lately and its really frustrating to get a monster below half health, in a long time wasting battle, only to have it suddenly turn invulnerable and full heal for no apparent reason. In the cases that this has happened to me I was doing little to no kiting, the monster was in or near the location where it originally starts, I was not using stealth, downed or anything else like that. I ran into this problem with Giganticus Lups in Arah exp. This was the first and most frustrating time. I tried doing that dungeon on several different occasions only to have my group give up because he just kept resetting. I have had this happen with an underwater veteran skale in Plains of Ashford near a skill point, the Giant boss rampaging in the town in Deissa Plateau, and also with a champian etton in Lornar’s Pass. It happened to me yesterday with the Spider Queen in which area I don’t recall and a few other times that I moved on without taking much note of it. Its frustrating, really frustrating, to me to keep wasting my time wanting to and trying to kill stuff in the world only to have them randomly reset. What is the problem here because I know its not something that I am doing wrong. Is someone aware of what is happening to me and already working on a fix? =(