Further analysis shows that it is related to changed file locations between the libnss3 versions. Some files were moved out of the nss directory.
Files in stable (libnss3 2:3.61-1+deb11u2): /usr/lib/x86_64-linux-gnu/libnss3.so /usr/lib/x86_64-linux-gnu/libnssutil3.so /usr/lib/x86_64-linux-gnu/libsmime3.so /usr/lib/x86_64-linux-gnu/libssl3.so /usr/lib/x86_64-linux-gnu/nss/libfreebl3.chk /usr/lib/x86_64-linux-gnu/nss/libfreebl3.so /usr/lib/x86_64-linux-gnu/nss/libfreeblpriv3.chk /usr/lib/x86_64-linux-gnu/nss/libfreeblpriv3.so /usr/lib/x86_64-linux-gnu/nss/libnssckbi.so /usr/lib/x86_64-linux-gnu/nss/libnssdbm3.chk /usr/lib/x86_64-linux-gnu/nss/libnssdbm3.so /usr/lib/x86_64-linux-gnu/nss/libsoftokn3.chk /usr/lib/x86_64-linux-gnu/nss/libsoftokn3.so /usr/share/doc/libnss3/changelog.Debian.gz /usr/share/doc/libnss3/copyright /usr/share/lintian/overrides/libnss3 Files in unstable (libnss3 2:3.77-1): /usr/lib/x86_64-linux-gnu/libfreebl3.chk /usr/lib/x86_64-linux-gnu/libfreebl3.so /usr/lib/x86_64-linux-gnu/libfreeblpriv3.chk /usr/lib/x86_64-linux-gnu/libfreeblpriv3.so /usr/lib/x86_64-linux-gnu/libnss3.so /usr/lib/x86_64-linux-gnu/libnssckbi.so /usr/lib/x86_64-linux-gnu/libnssdbm3.chk /usr/lib/x86_64-linux-gnu/libnssdbm3.so /usr/lib/x86_64-linux-gnu/libnssutil3.so /usr/lib/x86_64-linux-gnu/libsmime3.so /usr/lib/x86_64-linux-gnu/libsoftokn3.chk /usr/lib/x86_64-linux-gnu/libsoftokn3.so /usr/lib/x86_64-linux-gnu/libssl3.so /usr/share/doc/libnss3/changelog.Debian.gz /usr/share/doc/libnss3/copyright /usr/share/lintian/overrides/libnss3 QUICK FIX Manually creating a nss directory with symlinks to the shared objects appears to fix the problem. However, that is not a good solution as it could have undesired side effects. I am not sure whether it is the job for libnss3 or evolution maintainers to fix this. Regards