If you have folders that have the same name, actions performed on either, only are applied to the first one in tree.
Any action you make to to ParentFolder2\MyFolder, is only applied to ParentFolder1\MyFolder
I see this is a long-standing issue. I’ve just rediscovered it.
I had a folder at the root called “Bulk”, in which I put news feeds that are too high-volume to read everyitem. So sometimes I just mark the whole thing as read.
I wanted to split it up and have a News/Bulk and an Opinion/Bulk folder. I created two new sub-folders, and tried to move the items.
Well some of them worked, and some of them didn’t. And a few of the feeds got deleted. I re-added the deleted feeds, and selected the News/Bulk folder. They appeared in the Opinion/Bulk folder, and I cannot move them from there.