So fun fact: Samba shares do not support the question mark as a part of the file name. Also, fun fact: ext4 does. Also, fun fact: when copying large amounts of files in KDE plasma, clicking "yes to all" may conceal the fact that some of these files are not copied. Also, fun fact: blkdiscard is effective.

Legit fun fact though: the NTFS file system does support ? as a part of the file name.

@snappyl Technically NTFS is superior because it allows all Unicode codepoints except for backslash in filenames, while Unix filesystems allow all characters but NUL and forward slash.
However, even with the rawest means to access files available on Windows you cannot make use of that.
@pointingdevice oh yeah definitely. NTFS is pretty decent from a feature set perspective. In the past, I have had fun making files with “bad” characters in the file name in something like a GIT Bash window on a windows host to see what explorer did with them. It’s just that I messed up in this case and had a few files nuked. Live and learn!