option drag to duplicate naming sequence
Lately, when duplicating files and folders by option-dragging, the finder has been failing to name the duplicates correctly. It should be incrementing the number after the space but it seems to be bugged and rather than incrementing, it keeps adding another "space" and "2". The screenshot shows a folder containing rounds of revisions where I used to use this functionality but now it has stopped working.
I have tried relaunching finder, restarting the computer, and updating the os.
iMac Pro, macOS High Sierra (10.13.3)