"Generate LODs" can produce lighting bug on imported mesh (glb), camera angle dependent

[narcissawright]

Tested versions

Godot v4.2.1.stable

System information

Windows 10.0.22631 - Vulkan (Forward+) - dedicated AMD Radeon RX5600 (Advanced Micro Devices, Inc.; 31.0.22023.1014) - AMD Ryzen 7 3700X 8-Core Processor (16 Threads)

Issue description

when using "Generate LODs", from some camera angles the lighting on the imported mesh suddenly changes.
I've confirmed it happens in game. seems to happen as long as the scene is lit, regardless of worldenvironment settings.
video of lighting bug, only present when importing with "Generate LODs":

2024-03-11.13-23-17.mp4

Steps to reproduce

1. Import attached glb file (below)
2. Right click the file and open as New Inherited Scene
3. Move the camera to examine the ramp from various camera angles.
4. Import again with "Generate LODs" disabled
5. The bug disappears.

Minimal reproduction project (MRP)

the mesh in question (glb file) is attached here in zip form:
level1mesh.zip

[mrjustaguy]

Related to #81995