Description:
KDE Plasma 5.16.4 Global Menu is showing two sets of menus in all LibreOffice components.  The leftward one works, the second has pulldown menus, but the options are greyed out and don't work.   I was using the 6.1.x version of LibreOffice that was in Ubuntu 18.04 LTS repos without this problem.  I updated to the 6.2 and then 6.3 version from libreoffice/ppa, and experienced the problem in both of those versions of LibreOffice.

Steps to Reproduce:
1. Enable Global Menus in KDE Plasma 5.16.4.  (I am using KDE Neon, global menu is embedded in panel)
2. Open either LibreOffice 6.2 or 6.3
3. Problem should be visible immediately

Actual Results:
LibreOffice opens the global menu twice

Expected Results:
LibreOffice should only open one global menu


Reproducible: Always


User Profile Reset: Yes


OpenGL enabled: Yes

Additional Info:
Version: 6.3.0.4
Build ID: 1:6.3.0-0ubuntu0.18.04.1~lo2
CPU threads: 4; OS: Linux 4.15; UI render: default; VCL: gtk3; 
Locale: en-US (en_US.UTF-8); UI-Language: en-US
Calc: threaded