For a long time now the fire damage of enemies has been completely broken, especially on higher level missions. The damage and tick rate is so insane that it doesnt matter what defenses you have what health, what defensive perks/items/passives, the damage just completely melts you. And most importantly compared to all other damage from enemies its completely off the charts, so far so that it made me and others completely avoid playing high level missions with flame thrower enemies. Even using a Rosarius force field only helps for a moment, when its on CD you die anyways.
The damage and/or tick rate needs a complete rebalance, its broken beyond belief.
Here a video showcase of how ridiculous it really is.
Warhammer 40K: Inquisitor Martyr - Enemies broken Fire damage - YouTube