Anyone know how to do it? I couldn't find anything.

It's some sort of glitch involving the riot shield, not sure if it's invisible and stationary or it acts like it's always in front of you or what. Here's a video of the supposed glitch with artemis saying "It's definitely the barricade glitch. We are aware of it and looking for a solution."

/watch?v=YtjvVSHsT_g