Substances are never generated

Whenever I check the “generate on load” checkbox in the substance, I can see my objects being blue, but after a while they turn normal. I suppose this is because it takes some time to generate the substances. But why aren’t they generated on level load, before the game actually starts?
Another issue is if I disable the “generate on load” property, some of the substances are never generated (they remain blank(blue) forever).

How can I fix this issue? I’ve been fighting with it for over a month now.

If you check generate at load, the level should not start before all substances are generated and you shouldn’t see any popping, if you do, you should log it as a bug.
When you uncheck it, the substances will only generate when you tell them to (through script) indivually, allowing you to stream the generation.