I haven't been able to download a folder. I didn't find where it is on my device - quickpik at least didnt find -when I make it available offline, so I had to select all files in a folder to really download them.
Romeo R. commented
Please, add the ability to sync the folder with phone, like with pc
Unbelievably dysfunctional app from such a reputable company
Colin Chambers commented
Yep, OneDrive needs a download folders facility