Hello there! Source 2, HLA tools and hammer editor noob here. I've been tinkering with the workshop tools for the past couple of weeks or so and been having a great time.
Recently, as in the last couple days or so, I've started having lighting issues that are throwing a wrench in the workflow.

For context, I am running an AMD build and up to a couple days ago everything was working fine and every build was successful and lighting looked great.
However, after what I assume was a bad update it's been hit and miss on getting a build that actually looks correct anymore.

I'm attaching a few images that show how lighting looks in-game. They're terribly broken reflections, apparently, and are usually in bright red, green, blue, or neon colors.
Perhaps I'm missing something really obvious, but so far I've tried rolling back GPU driver versions, uninstalled Windows updates, etc. Even the default template basic setup presents the problem after lights are built.


Here are a couple of screenshots I've taken to illustrate what's happening:

screenshot1:
https://steamhost.cn/steamcommunity_com/sharedfiles/filedetails/?id=3000165014

screenshot2:
https://steamhost.cn/steamcommunity_com/sharedfiles/filedetails/?id=3000164850


Sometimes the lighting will look correct in the editor, but when the level is built it will look like the screenshots. Then, either after a retry or a few repeated builds
things get back to normal, until they break again.

if the env_combined_light_probe_volume is removed the issue vanishes but it's not exactly an option. A single cubemap in the level apparently is enough to trigger the issue.

This issue does not seem to happen anywhere in the release maps nor in any other game/software.

Building cubemaps and repeteadly rebuilding all lightning does seem to clear the problem occasionally, which only adds to my confusion and to the belief that perhaps
I'm doing something fundamentally wrong.


Any insight would be greatly appreciated about how I could go about debugging the problem.

Thank you all in advance for your time and attention!