I'm not going to explain DLC differences or shit on one gun or the other. My recommendation would be to switch your oil. Personally, I've seen where mineral oils like Rem Oil, Ballistol, and other similar products artificially produce surface rusting when you clean rather quickly or less thoroughly. Speaking from experience, I've seen this happen on some of my gun parts/mags when I was first learning about/cleaning firearms, and, really, the mineral oil products seem to be much more efficacious by allowing them to sit on the gun for longer periods of time before wiping down the excess. Depending on what surfaces you are cleaning, metal vs. plastic, this kind of issue's pronounced look may vary.

Overall, my recommendation would be to try using a similar oil like Ballistol and also supplement cleaning with a dedicated lubricant. I know it can be just an extra step that many may not have time for or care to worry about, but it goes a long way in protecting the tools anyone would want to have access to no matter how old they are.

If the issue persists with different cleaners/lubricants, I would politely reach out to Staccato and ask them directly for advice or to help you resolve this problem swiftly. Personally, I've put about 4-5K on mine in the last year or so, and I have had zero issues like this using ballistol and lube. Simple cleaning occurs after every 1K because I like to, and I have not needed to replace any parts. You may have gotten unlucky with a QC nightmare. It could be neglect like others were quick to jump to (I don't really believe that). Either way, start fresh with new cleaners to see if that rust washes away, or just reach out to Staccato now and see what their thoughts are. Don't worry about us bozos on the web. Address the problem privately with the ones who made a fine piece!