[2020] weapon level 40 and rogue agents in the dark zone

I have a couple of doubts and hopefully you can help me guys. i have the original game without dlc. I have noticed that I have a couple of level 40 weapons available in my inventory but I cannot choose them. This is because I must be level 40 and that I have to have the dlc? And speaking of the dark zone, I consider myself pretty good at it. But I have found that rogue agents are impossible to kill. I don't do any kind of damage to them and they kill me in 2 seconds. I guess they are level 40 while I am still level 30 and I don't know if that has anything to do with it. The same happens to me in the raid. the final bosses kill me with a single shot when I see that my teammates who are all level 40, they don't kill them as fast as me. and sorry for bad english.