Hey there!
I bought the my cloud home duo two months ago to share files with my girlfriend. Up to now, she had no time to deal with the new cloud solution. But yesterday she wanted to download some pictures to her iPhone out of the shared folder. Though she can watch, delete all files in the folder and even upload new files to the folder, unfortunately there is no download option in her iOS mobile app when you are in the shared folder. No problems in her private folders, though. However, when she uses the browser solution, she is able to download files from the shared folder. So she has enough rights to do that. (It’s even possible for her to delete files in the shared folder by using her mobile app!) Using the android mobile app, the topic is the same: No download option for user out of public folder.
There must be something wrong and I hope you can help me. My girlfriend was the reason why I chose a my cloud home duo instead of a my cloud ex2 ultra, since we wanted a very simple solution. Like this it does not satisfy our use case at all! 
