So, this could be from Tempest Rush Flurry, PoJ or Blinding Light. This also isn’t my video, a friend sent it to me. It is super super obvious he is executing this correctly. If you don’t feel like watching, he does 3 full stack flurries and one 70+ and not a single one does damage. This isn’t anything new, but I’ve never seen it happen so often.
https://www.youtube.com/watch?v=N6pv2oBofz0&t=81s