I can remember something at the start of the game that explained how these worked. The barriers that are all wrapped up in orange rope. Something about being able to cut through them. I’m at a camp now for the “Find and rescue Ethan Ross”mission and I can’t get into the encampment. Only way I see to get in is through the fence with the orange rope and I don’t see any prompt showing up to let me cut it.
You need to use explosives. Doesn’t help you keep cover but it’s the only way I know of. Do it from a distance and hide. Once the enemies are cool again you can go in and clean up.