searx, matrixsynapse: App installed but package not installed

FreedomBox v22.23 on Debian Bullseye vagrant box

1. Run all functional tests.
2. Dist upgrade to Bookworm.
3. Run all functional tests.

The Searx app is enabled, but somehow the package is not installed:

root@mybox:/home/vagrant# apt policy searx
searx:
  Installed: (none)
  Candidate: 1.0.0+dfsg1-1
  Version table:
     1.0.0+dfsg1-1 500
        500 http://deb.debian.org/debian bookworm/main amd64 Packages

If I uninstall and then re-install the app, then it is installed and working as normal.