Quick answer: Unity ShaderVariantCollection missing keyword combinations enabled at runtime via script? Collection captures editor warmup; script keywords need to play in editor first.
Authored a 'special-mode' keyword via script; build strips the variant; runtime pink.
Play in editor to capture
Play the game; trigger every keyword combination. Collection records.
Or manually add variants
Edit the collection; add the missing combos by hand. Explicit; verifiable.
Audit script-enabled keywords
Each script SetKeyword: verify it's in the collection.
“Variant collections are gameplay-driven. Editor doesn't see your runtime enabling.”
If you enable keywords via script, the variant collection audit is the cure. Document.