LibreOffice 126.96.36.199 (used with QT5 interface)
KDE5 (Plasma 5.12.8, Framework 5.55.0, QT 5.9.7, Widget Style Breeze)
In environment above, by standard settings the scrollbars don't have arrow buttons for stepping.
But it's possible in KDE System Settings to configure the scrollbars with one or two arrow buttons for stepping.
This works fine for the KDE applications, but not in LibreOffice.
In LibreOffice with 'one or two buttons' configured in KDE, there are small areas above/below on vertical and left/right on horizontal scrollbar, but they are 'empty', but I can use by 'blind' clicking on them the stepping functionality.
So I assume there is something wrong with the breeze style in LibreOffice, since when I switch to another Widget Style e.g. Fusion in KDE settings, I can see the buttons in LibreOffice (limited to one arrow button, since Fusion only allows one arrow button).
Thank you for reporting the bug.
Could you please try to reproduce it with the version 188.8.131.52 of LibreOffice
from https://www.libreoffice.org/download/libreoffice-fresh/ ?
I have set the bug's status to 'NEEDINFO'. Please change it back to
'UNCONFIRMED' if the bug is still present in the latest version.
thanks for your help.
I installed version 184.108.40.206 (parallel to existing version to /opt/libreoffice6.3), but same problems here.
Without KDE integration module (libobasis6.3-kde-integration-220.127.116.11-2.x86_64.rpm), I get the 'rough' standard style with scrollbars and one arrow button for stepping.
With KDE integration module, I get a nicer style (Breeze), but no arrow buttons for stepping.
to be more precise:
With KDE integration module, I get a nicer style (Breeze), but no VISIBLE arrow buttons for stepping.
As I described above, the buttons are unvisible, but work.
Some user report this in Ask:
I test this in different SO, all test with LibreOffice Fresh 6.3.3:
Windows - Ok, see arrows
Arch|Gnome - Not see
LinutMint 19.2|Cinnamon - Not see
openSuse Tumbleweed|KDE - Not see
Kubuntu 18.10|KDE - Not see
Build ID: 775a06361639ffc539fda20d44b9610c98005d9b
CPU threads: 4; OS: Linux 5.3; UI render: default; VCL: kf5;
Locale: en-GB (en_GB.UTF-8); UI-Language: en-US
Description how to enable those arrows in KDE Plasma settings: 
Currently kf5 VCL plugin doesn't use native Qt widgets. Implementing this would probably fix the issue "automatically", but is quite a lot of work.
It may well be possible to fix this specific bug independently, though.
(In reply to Michael Weghorn from comment #5)
> Confirmed with
> Version: 18.104.22.168.alpha0+
> Build ID: 775a06361639ffc539fda20d44b9610c98005d9b
> CPU threads: 4; OS: Linux 5.3; UI render: default; VCL: kf5;
> Locale: en-GB (en_GB.UTF-8); UI-Language: en-US
> Calc: threaded
> Description how to enable those arrows in KDE Plasma settings: 
> Currently kf5 VCL plugin doesn't use native Qt widgets. Implementing this
> would probably fix the issue "automatically", but is quite a lot of work.
> It may well be possible to fix this specific bug independently, though.
>  https://forum.kde.org/viewtopic.php?f=67&t=150658
the strange thing is, that in principle the KDE5 Breeze Stile 'feature' to enable the buttons works in LibreOffice, but they are unvisible in LibreOffice.
It's not of big importance, but for my opinion kde5&Breeze is from design/layout not really barrier-free (which has nothing to do with LibreOffice, but with KDE). Th scrollbars are far to small and not suitable for some people.
This won't work without using the new "weld" theming API.
*** This bug has been marked as a duplicate of bug 130857 ***
*** Bug 138014 has been marked as a duplicate of this bug. ***