Interesting....
I have been looking into the rules and restrictions regarding folder and filenames.
Reference:
https://learn.microsoft.com/en-us/windows/win32/fileio/naming-a-file
Have not noted anything that could be going astray there.
However, if you are willing, do a bit of experimenting. Try renaming and/or flagging the files without special characters, the word "check", or anything else you are willing to try.
Strongly suggest that you experiment on folder and file copies being sure that all original folders and files are backed up and otherwise protected.
Identify the copied folders as test folders.
Try something like Patient_Zero vs Patient_Zero_Confirm.
Test by renaming folders and files directly in Windows and in Agent Ransack.
And search for "Confirm".
The objective being to find something that does again work for Agent Ransack.
Be very deliberate and methodical.
If the test folders and files get corrupted or messy. Delete and try again.
Post what you find and learn.
Unfortunately I do not have some "instant answer". However someone else may spot some issue or problem and post accordingly. I have no problem with that.