Thanks Tony, but that doesn’t really apply in my case.
I just copied a group of files within the folder, by highlighting the group, then either right-clicking, drag and paste, or right-click, select copy, then paste.
Even if I just copy one of these files, I get the same behaviour.
Since it only happens with MBL and not another local drive, I suspect something with network somehow interacting with these particular file properties… dunno… just thought I’d check if it’s a common occurrence.