Right-to-left and left-to-right buttons in Ubuntu

I have these useful buttons on my Formatting toolbar in the Windows version of LO, but in Ubuntu, they refuse to display on the toolbar, although the commands exist in the Customize menu.
The function is accessible by digging into the paragraph menu, but still, I would like to see it on the toolbar.
LO 6 (Ubuntu version)
Kubuntu 20.04

they refuse to display on the toolbar

Have you tried to reset your LibreOffice user profile?

Related to your response:

Is your kubuntu LibreOffice install an “initial install” (never updated, just installed recently)? If yes - check my answer ti this question: menu bar is just boxes, there are no words.

I tried deleting my LO user profile, it did not help. I am running Kubuntu in a virtual machine. I suspect the issue might because I have a custom theme, maybe it does not support all icons and buttons.

In the meantime, I noticed that the buttons do display properly in LO on my MX Linux distro, which is running on-the-metal.
LO 6.1.5.2


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