Spinning beach ball when moving files and folders within their parent folder
I've not noticed this problem before until I bought my new MBP 15" with Sierra (10.13.1):
Scenario:
Folder A containing:
File B
Subfolder C containing files D, E & F
If I select files D, E & F and file B, then drag them into Folder A, I instantly get the spinning beach ball, which requires relaunching Finder. However, if I just drag files D, E & F to folder A, and then drag file B to folder A it works fine. Yes, I know it's actually redundant to drag B into a folder it's already in, but the point is it used to work fine under all previous OS versions. I'm assuming it's to do with moving a mixture of files and folders that originate within the tree under their parent folder, which may be confusing Finder. Any ideas?
MacBook Pro (15-inch, 2017), macOS High Sierra (10.13.1)