Dear maintainer,
I have found the reason why /usr/lib/x86_64-linux-gnu/qt5/plugins/okular/generators/okularGenerator_poppler.so was linked against libtiff.so.5 on my system. This was due to a local recompilation of libpoppler on my bulleyes installation (that I have just migrated to bookworm). The faulty library (libpoppler.so) was still installed in /usr/local/lib ... Removing it solves the problem. Sorry for the noise. Frédéric