Bug: PBR materials are over-brightened in many cases

[Wheattttt]

Describe the bug

IN EDITOR:

ALL PBR materials are over-brightened in-editor, regardless of conditions. See below:

IN GAME:

PBR materials become over-brightened when lit by projected textures. This does not happen with other light sources, only projected textures. I've heard some say this may be intentional, or more "physically accurate", but if that were so, it would happen with static lighting as well, which it does not. See below:

Additional edit: I am aware this is a duplicate, but the last issue I've seen regarding this bug didn't go fully into depth, and only captured the hammer side of the bug.

To Reproduce

Observe any PBR material in hammer to see the hammer side of the bug.
Open the example map below to see the in-game side of the bug.

Issue Map

BSP, VMF, and all custom textures and materials are supplied in this ZIP.

issuemap_pbroverbrightening.zip

Expected Behavior

Projected textures should have equal (or at the very least visually similar) effects on PBR textures and LMG textures.

Operating System

Win 11