If it wasn't a problem before, I think it is now. From all the market connector data I'm seeing, there's barely anywhere with more than 20 tonnes of the things, and they're being eaten up by cmdrs as soon as they spawn. I've just visited 5 seperate systems and limped away with a mere 8 out of 132 I need of the things (and that was with waiting 20 minutes for a restock at one of them). All the initial supplies of them have been exhausted and the respawn rate seems much lower than CMMs.
You probably just need to go a bit further. (If you're using Inara's commodity search, set a filter of "minimum 100 stock", or maybe even "minimum 500", or you'll just get a page of the nearby empty ones)
The sources on the edge of the bubble have two problems:
1) Everyone is going for them
2) They tend to be smaller economies in the first place, so have tiny restock rates
Closer to the centre of the bubble there are plenty of large (orbital refinery) economies with higher stocks and restock rates, that are also further from most of the action.
They're rarer than any of the other goods except Emergency Power Cells (now that CMM have been multiplied by about 5000) but on the other hand they're not needed in anything like the bulk CMM is either.
If you have a player faction your squad identifies with, when you colonise a system are they supposed to be present along with the faction you got the colonisation status from? As my second colonisation system doesn't have my player faction in the system?
Have you finished building the initial starport yet? Your squadron's faction gets added in 3rd place when you do that, not before.
And how do I change from a Colany Economy?
Construct things with the "System Economy Influence" property.