Impress: weird artefacts with arrows at slideshow

When in a slide I have an arrow pointing to text, and the items appear together by animation, then the text shows artefacts in the form of black horizontal lines, like this:

Is this an actual bug, or am I messing up with something?

EDIT: Happening with various systems (Xubuntu 16.04, Xubuntu 18.04, Ubuntu 18.04) on different machines, since version 5 at least (maybe even earlier).

EDIT2: Here’s what I see in Tools > Options > LibreOffice > View

image description

Have you ever looked, if you openGL is turned on?

In the menu Extras>Options>View. Remember the settings and test the settings in “Graphics Output”, especially in OpenGL.

See also:

Thank you for the input. I added the available options in the open post.
There’s no specific OpenGL setting, but there are two about anti-aliasing and hardware acceleration. I experimented with those, but to no avail.

I’m sorry, the information was for Windows.