I think it's just part of the normal cycle of the tank, the tank is only 2 weeks old. Expect this and worse for the next 2 months until the tank matures.
Also, I don't know why people have issues with distilled. It's not ideal, but I still haven't seen anyone actually have issues with it. I believe it tests close to or at 0 TDS, and I've never seen anyone get copper from it, and it was what I topped up my new cube with for the first few months of having the tank. There is merit in the discussion, but the fact is nobody has ever poisoned their tank and posted about it on ReefCentral to my knowledge.
Here is an example of an old thread where this was discussed by people who know much more than you, I, or anyone else in this thread about the process, and their results and recommendations.
Distilled: use at your own risk, but nobody has poisoned their tank with it or detected TDS or copper from it. I've used it without issue and it makes sense if you don't have easy access to RO/DI water. Probably cleaner than the machines at the supermarket, because as mentioned earlier, those may or may not ever have their filters changed out. I've also heard of those only having carbon filtration on them as well, not full RO units. So it's largely all YMMV (your mileage may vary) unless you are making the water at home yourself with your own unit that you are maintaining and testing.