Puppetdb fails to install

I’m trying to add puppetdb to our foreman installation. The puppetrun fails.

Puppetdb up and running

Foreman 1.20.2, Proxy version 1.20.2

Tried most recent puppetdb module 7.1.0 and version 6.0.2

Error: Systemd start for postgresql-9.6 failed!
journalctl log for postgresql-9.6:
-- Logs begin at Wed 2019-05-15 16:39:29 CEST, end at Wed 2019-05-15 16:53:25 CEST. --
May 15 16:53:25 foreman.infosys.ifv.systems systemd[1]: Starting PostgreSQL 9.6 database server...
May 15 16:53:25 foreman.infosys.ifv.systems systemd[1]: postgresql-9.6.service: main process exited, code=exited, status=1/FAILURE
May 15 16:53:25 foreman.infosys.ifv.systems systemd[1]: Failed to start PostgreSQL 9.6 database server.
May 15 16:53:25 foreman.infosys.ifv.systems systemd[1]: Unit postgresql-9.6.service entered failed state.
May 15 16:53:25 foreman.infosys.ifv.systems systemd[1]: postgresql-9.6.service failed.

Error: /Stage[main]/Postgresql::Server::Service/Service[postgresqld]/ensure: change from 'stopped' to 'running' failed: Systemd start for postgresql-9.6 failed!
journalctl log for postgresql-9.6:
-- Logs begin at Wed 2019-05-15 16:39:29 CEST, end at Wed 2019-05-15 16:53:25 CEST. --
May 15 16:53:25 foreman.infosys.ifv.systems systemd[1]: Starting PostgreSQL 9.6 database server...
May 15 16:53:25 foreman.infosys.ifv.systems systemd[1]: postgresql-9.6.service: main process exited, code=exited, status=1/FAILURE
May 15 16:53:25 foreman.infosys.ifv.systems systemd[1]: Failed to start PostgreSQL 9.6 database server.
May 15 16:53:25 foreman.infosys.ifv.systems systemd[1]: Unit postgresql-9.6.service entered failed state.
May 15 16:53:25 foreman.infosys.ifv.systems systemd[1]: postgresql-9.6.service failed.

Does anyone recognise this problem?