Endgame Graphics Bug

I am having a serious issue with graphics during the endgame sequence. Cutscenes and some parts of the final battle with Elgarn'an have a significant flicker, and in some parts all that is visible of Elgarn'an  is his hair. This is contained to the final area of the Archon's Palace, but makes the scenes just before the final battle unwatchable due to flickering, or simply because none of the scene is actually visible. I have attempted to play with lower graphics settings and turning off ray tracing, as well as turning off HDR on my computer entirely, but the effect remains. Playing on PC with Nvidia 4090 graphics card and an Intel 13900k CPU.

Flickering starts at the point where the archdemon bites Solas, and continues until Elgarn'an is defeated. It is most noticeable in the cutscenes, but can be seen in the environment on the ramp up to the door to the throne room and during the fight. The effect is worst on Elgarn'an himself, but in some cases even Rook and their companions are also reduced to floating hairstyles.