Steve, may I ask if you're running NVDA as portable? Truthfully, I personally cannot replicate any of the problems you're having w/my Windows 10, latest build,. Can you tell us:
Firstly, I am not running as portable on the machines tested.
1) How are your views set?
Details, This PC by default, no Preview Payne, no Navigation Payne.
2) What details do you have enabled?
All of them I think.
3) Is your File Explorer maximized?
Yes. I even tried Windows+Up Arrow to make sure it was.
I do know that portable NVDA just does not read lists as well as when it's actually installed. I don't know if this is because it's better able to hook into various machine processes or what, but that is something my experience has definitively shown me.
Well I haven't found portable to be any worse for me thus far, but now, Explorer is completely unusable on all my machines. When you enter a folder, it reads out the first file name, but from then on, it is silent.
All the best