I use Find Duplicate Files, use the "MD5 Checksum" mode, all checkboxes unchecked except "Clear Previous Results" and "Search inside subfolders." It finds no duplicates even though I know for a fact there are duplicates. Dopus 12.10 has the prooblem worked OK in 10
Please post a couple of screenshots showing:
The lister with the Find Duplicates panel set up as you are using it, so we can see the exact settings and which folders are being searched.
A pair of files you think it should be finding, after running the Edit > Calculate MD5 Checksums command on them, with the MD5 column visible so we can see the files are identical.