Weird font rendering when used within Konsole

I am using Konsole to run ssh to a remote system using byobu.
The monospaced font used is Hack (hackrf v2015.07.2-6).

When I coonect and byobu has been enabled, then the a slice (1 or 2 pixel high) in the lowest part of the font get truncated and not displayed.
So, for example, it is impossible to tell 'q' from 'g' apart and the underscores '_' are not displayed at all.
When I use the readline library to edit the characters, those from the cursor position to the right are displayed correctly, those on the left of the cursor appear as being lower with the truncated slice. The characters on the right are displayed a little bit higher than those on the left.
Please, see attached screen shots.

ProblemType: Bug
DistroRelease: Ubuntu 16.04
Package: byobu 5.106-0ubuntu1
Uname: Linux 4.8.7-040807-lowlatency x86_64
ApportVersion: 2.20.1-0ubuntu2.1
Architecture: amd64
CurrentDesktop: KDE
Date: Fri Nov 18 12:07:53 2016
PackageArchitecture: all
SourcePackage: byobu
UpgradeStatus: No upgrade log present (probably fresh install)