Hi, I have a DL2100, and it’s all the same in this regard. I have no issues uploading from my iPhone nor my wife’s. It all works. In fact, I have made folders for each of us to move new uploads into so we keep them separate; her stuff and my stuff.,
So, my first though, since your issue is unique, is to un-install the MC app from iPhone then re-install it. Assuming this fixes things, there is another big issue you will run in to; incomplete uploads; unless you read this post of mine in the forum. Good luck with your tasks.