Comment 19 for bug 1913775

bluppfisk, if you have installed the jammy packages on impish, enabling impish-proposed won't offer the update because the version is greater in jammy.

You will need to specify the version number to downgrade to the impish proposed update:

  sudo apt install libgtk-3-common=3.24.30-1ubuntu1.1 \
    libgtk-3-0=3.24.30-1ubuntu1.1 libgtk-3-bin=3.24.30-1ubuntu1.1 \
    gtk-update-icon-cache=3.24.30-1ubuntu1.1 gir1.2-gtk-3.0=3.24.30-1ubuntu1.1