Windows 10. Explorer++ v1.3.5.531 (x64) and v1.4.0.2293 (x64).
On NTFS storage, if I rename a file by changing case only, e.g "new file.txt" to "New File.txt" the file disappears from the list. A quick refresh (F5) will return the file to the list with the changed case.
On FAT32 storage, the same renaming (case change only) seems to work, but after refreshing the list, the filename reverts to its original case.