Yup, same. Initially thought it's a driver problem, because on PC the artifacts are present on AMD GPU-s / iGPU-s. But, if played on NVIDIA card - NVENC hides those artifacts, similarly there are no artifacts when video is played on Android. Didn't check on Intel, tho.
I ended up trying a bunch of stuff with re-encoding etc, in short - video indeed has some initial compression artifacts, which are most likely the reason for the "green explosion" on AMD cards. There are far fewer of them and they don't look as bad, but they are still noticeable. The worst part - any attempt to fidget around with fffmpeg or edit the video - just "bakes in" those initial artifacts and makes them permanently visible even on NVIDIA.
I also checked several previous videos and everything since late June is affected. He started to output videos in 4K at that point, maybe messed up some settings and didn't notice since NVIDIA conveniently hid it.
If anyone here is subbed on P or F, would be nice if you could reach him about this.
For reference:
"Initial" artifacts:
https://freeimage.host/i/initial-artifacts.FPADm4S
"AMD" artifacts:
https://freeimage.host/i/amd-artifacts.FPADbG2
