Are they produced only on colonies that have had ancient ruins / ancient constructs on them? Or is it just a few colonies will start making them randomly?
Sorry, been away with my team for preseason and just back.
It's random and treated like any other goods so some colonies will produce it some others will not. You can adjust when the colony starts producing them or if they are rare (less chance to generate) from the same tab. I have tested it now for a very long time and I never had issues. So I would consider it as an official fix while waiting for Steve to double-check why they are not active from the beginning or what under conditions they should spawn.