Issue with Factor 5 games at higher internal resolutions

[iSynic]

Retroarch Windows, using Parallel RDP via Mupen64Plus-Next core (forgive me if this is the wrong place, I initially posted this on the Parallel-n64 Core GitHub page but this seemed like a better fit).

I initially noticed some distracting visuals while playing Indiana Jones and the Infernal Machine. I've since tried other Factor 5 games (Rogue Squadron and Battle for Naboo) and they all seem to have a similar issue:

https://drive.google.com/file/d/1xRRiHM86gDuL1n4ly83bbGXJbnRo8-eu/view?usp=sharing

If you open the screenshot I provided, zoom in and look at the wall to the left of Indy. If you were to see it in motion, you could spin Indy and the artifact shapes would all stay the same even as the graphics underneath changed.

I'm playing with 4x resolution. I've tried disabling the VI effects but it didn't change anything. The artifacts themselves never seem to change, it's almost like they sit on top of the rendered graphics. They're especially visible in darker/shadowed scenes.

I'm not sure if this is a bug, or if Factor 5 had some funny overlay on top of their rendered graphics that is more visible as the internal resolution is scaled up (custom dithering or something?).

[delta7890]

Can confirm this occurs in Rogue Squadron, and is most noticeable during cutscenes. Played in Mupen64Plus + Mupen64Plus GUI.