Cannot decrypt file encrypted with enQsig

[Felix E. Klee]

*Update:* Yesterday, I was reading the [GnuPG wiki page on
SmartCards][1] due to another issue. At its bottom I found listed as
known bug:

  * Encrypted message with 3DES can't be decrypted with OpenPGP Card
    (V2.1, V3.3 without fix)

      - Due to the bug, it results: Missing item in object <SCD>

      - See: https://dev.gnupg.org/T3576

Well, indeed if I encrypt a message with 3DES, I cannot decrypt it with
my SmartCard:

    $ echo "Hello, world!" >foo
    $ gpg -e -r felix.klee at inka.de --personal-cipher-preference 3DES foo
    $ gpg -d --debug=crypto foo.gpg
    […]
    gpg: encrypted with 4096-bit RSA key, ID 04FDF78D1679DD94, created 2
    016-12-17
          "Felix E. Klee <felix.klee at inka.de>"
    gpg: public key decryption failed: Missing item in object
    gpg: decryption failed: No secret key
    gpg: secmem usage: 0/32768 bytes in 0 blocks
    $ gpg --version
    gpg (GnuPG) 2.2.9
    libgcrypt 1.8.3
    […]

“Missing item in object” is the same message that I get when trying to
decrypt the enQsig encrypted message! So, perhaps enQsig is using 3DES.
*How do I find that out?*

Also, I don’t understand: I was assuming that all the card does is
decrypt my session key using my private 4096 bit RSA key. *If the
session key is a 3DES key, why should the card care?*

[1]: https://wiki.gnupg.org/SmartCard