MyMPD fails to update artwork.

[agent_kith]

My ooops :-)    should be o!-mpd
http://ompd.pl/
https://github.com/ArturSierzant/OMPD

though I haven't really investigated it and perhaps will just run with LMS and material-skin for now until I can figure how to install the My-Mpd repo...
Your link fails as the version it reports is 22.04 and the instructions expect Debian 11.

This should work, try and run these from a SSH and see what happens

Code:

if [ -f /usr/share/keyrings/jcorporation.github.io.gpg ]; then
    rm -f /usr/share/keyrings/jcorporation.github.io.gpg
  fi

  curl http://download.opensuse.org/repositories/home:/jcorporation/Debian_11/Release.key | \
    gpg --no-default-keyring --keyring /usr/share/keyrings/jcorporation.github.io.gpg --import

  # Get Debian VERSION_ID from os-release file
  MYMPD_PATH=""
  source /etc/os-release
  if [ "$NAME" == "Ubuntu" ]; then
    MYMPD_PATH="xUbuntu"
  else
    MYMPD_PATH="$NAME"
  fi
  # Add JCorporation APT repository and ensure releases are signed with the repository's official keys
  cat <<EOF > /etc/apt/sources.list.d/jcorporation.list
   deb [signed-by=/usr/share/keyrings/jcorporation.github.io.gpg] http://download.opensuse.org/repositories/home:/jcorporation/${MYMPD_PATH}_${VERSION_ID}/ ./
EOF
  apt update
  apt install -y mympd