I'm sorry if I stated the progress we've been making in a passive-aggressive way. I do appreciate the responsiveness you've been giving in the responses. There's been multiple solution threads going along different directions, and your most recent question was a cognitive jump for me.
Your pointing out the missing Application Menu in Konsole and Kate wasn't something that I had noticed earlier. The conclusion that this brings -- which may have been clear to you, but wasn't to me -- is that the problem is not with LibreOffice per se, but something else.
The Application Menu that appears in the screenshots that I took were the result of having made the changes in Application Style ... Window Decorations ... Buttons ... dragging and dropping "Application menu" into Titlebar, as you had directed. In removing that (back to the original state so that it's not in the Titlebar), neither Kate nor Konsole have an Application Menu. And yes, starting LibreOffice now still doesn't have an Application Menu.
On my bringing up the example from Francesco, I trying to respond to your question about the Global Menu. I thought that the Menubar pane on Francesco's KDE setting was where the Global Menu gets set. If I'm wrong, then I really still don't understand where the GlobaLMenu gets set. Since Manjaro has a rolling release, and I didn't have this problem in my system from April through July, I thought that location of this Menubar style setting might be something that had moved to another place in KDE settings in the August update/upgrade.
I now don't understand what you mean by the "standard User profile". When we were dealing with LibreOffice only, I thought that you meant the "4" directory as the User profile. Now, it seems like we're dealing with a bigger issue.
My tone may be one of frustration, because I've really liked Manjaro KDE, since I switched to it from Kubuntu, a few months ago. I'm working on a deadline where I'm using LibreOffice, so I've had to resort back to Kubuntu in order to get work done. I'm now booting into Manjaro ONLY to do the diagnosis and changes in this thread.
I appreciate that a shared /home partition has risks. The "real" data for my work isn't on the /home partition (which is an mSATA SSD), but actually on an NFTS-mounted SATA partition that is physically separate. The standard installed directories (e.g. Documents, Music, ....) don't have working data in them. This allows me to make changes (i.e. reformat if necessary) the /home partition when I'm updating or changing between different distros, if there's a problem. The use of a shared /home partition is quite old for me -- it started with Ubuntu 8.04, then 10.04, 12.04, 14.04, 16.04 and now 18.04 -- but my crossing over from Debian-based distros to the Arch-based distro is something that I've only been doing for the past few months.
I would like to use Manjaro KDE as my primary desktop and distro, because I've found the community forums to be responsive, and I like the AUR. I can live with the missing Application Menu in Kate and in Konsole, because they're not mission-critical for me, and there are other alternatives that could be installed. I cannot, however, work with a missing Application Menu in LibreOffice. I even tried installing OpenOffice yesterday, to see if I could use that within Manjaro KDE until something gets resolved, but the position of objects in Impress presentations appeared as shifted, so that's not going to work.
If your opinion is that there is no alternative to wiping the /home partition and reinstalling Manjaro, I can do that. However, since I've been using a shared /home directory as a way of working with multiple distros since 2008, if this is an incompatability across Debian and Arch distros, then I'll probably have to revert to using Kubuntu as my primary distro, and come over to Manjaro KDE when I really need something that is only available in AUR.
Thanks again for responding to this thread. I apologize that the response is so long, but now appreciating that the missing Application Menu isn't just a LibreOffice issue raises all sorts of questions and complications.