kmail address completion borked

[SA]

When filling in an address in kmail I get no suggestions until I've typed something and deleted it again and then it works as expected... was broken, then fixed and now broken again...

ProblemType: Bug
DistroRelease: Ubuntu 16.10
Package: kmail 4:16.04.3-0ubuntu2
ProcVersionSignature: Ubuntu 4.8.0-41.44-generic 4.8.17
Uname: Linux 4.8.0-41-generic x86_64
NonfreeKernelModules: nvidia_uvm nvidia_drm nvidia_modeset nvidia
ApportVersion: 2.20.3-0ubuntu8.2
Architecture: amd64
CurrentDesktop: KDE
Date: Fri Mar 24 21:48:59 2017
InstallationDate: Installed on 2016-08-03 (233 days ago)
InstallationMedia: Kubuntu 16.04.1 LTS "Xenial Xerus" - Release amd64 (20160719)
JournalErrors:
 Error: command ['journalctl', '-b', '--priority=warning', '--lines=1000'] failed with exit code 1: Hint: You are currently not seeing messages from other users and the system.
       Users in the 'systemd-journal' group can see all messages. Pass -q to
       turn off this notice.
 No journal files were opened due to insufficient permissions.
SourcePackage: kdepim
UpgradeStatus: Upgraded to yakkety on 2017-01-04 (79 days ago)

[dino99 (9d9)]

This is an unsupported release now. Please think to install the next LTS 'Bionic 18.04'

http://cdimage.ubuntu.com/ubuntu-next/daily-live/current/
https://www.omgubuntu.co.uk/2018/02/ubuntu-18-04-minimal-install-option