This is an intended behaviour. All of the game's resources and factories are fully simulated, so if AI factions don't deliver resources, you might have to to it yourself, as part of the game's economy. This is actually a large part of how you can get richer !

I see it as an opportunity, but it's kinda hard to read and since steel is some kind of lifeblood I'm kinda worried the whole thing might cascade through the economy. So far I haven't seen any more bottlenecks. I've witnessed NPC trading with my own stations so I found that strange.