Using Kleopatra - (apparently) a file may be signed using a detached signature only, while GPG (and GPA) will allow an included signature which Kleopatra does verify (failed-no data).
Test: Use gpa, or use command prompt gpg --sign file, to sign (only) a file. Ask gpa to verify the signature, or use gpg --verify file, and all appears well. Now ask Kleopatra to verify the signature - fail.
Will someone please verify, and or explain the reason for this Kleopatra “feature”.