I observe something similar. Picture below presents 2 consecutive frames from the same cut. Sometimes this “burn” artifact develops slower (not that drastically like it is here).
I observed it twice earlier. First time it was sufficient to restart UE5. Another time it helped when I disabled Subsurface effects in tree materials. It started to reappear after I lowered resolution of textures (Max texture size) for some of objects. Currently one time it appears, second time it does not.
In the project I am using Quixel Megascans and “Temples of Cambodia” assets, Lumen, Nanite in UE 5.3.2.
