I have the exact same problem equipping the first armor plate with DXR enabled playing Firestorm. I go to equip the armor plate for the first time in a round, game freezes for a few seconds and then resumes normally for the rest of the round. I also either crash to desktop, freeze up, or get stuck in a loading loop every 3rd round of Firestorm on the Halvoy map loading screen. Wish there were a fix for this, the game mode has been out now for a significant amount of time... I have tried all the different trouble shooting things. This is a problem with the game or the drivers. Dice and/or Nvidia need to fix this.
Intel i7 8700 K (Stock Frequencies)
Aorus Z370 Gaming 7
Aorus RTX 2080 Ti
32 GB G.Skill F4-3200C16D-32GTZKW (XMP Enabled)
Samsung 960 Evo 1TB NVMe (Game installed on this)