WPS Office: a mistake?

I haven't become a big fan of the WPS office world yet. I use this software on my notebook, cell phone and tablet. However, I have noticed something for a long time that I can't get away. No matter whether on the notebook, cell phone or tablet. Microsoft Office does not have this part at all, as does all other Office programs.

Maybe one of you knows what that could be and if you can somehow switch it off? I get annoyed by dementia!

Here is a cell phone picture of this part:

This little triangle is meant above. Can you somehow put that away on a notebook, cell phone, tablet? : /

This is just a margin marking that is not printed out anyway.

How to display them, I don't know. If necessary, just set no margin for digital documents only.

I won't print anything anyway. However, it bothers me when I work.

I don't see a triangle here, if you programmed the software yourself you can certainly delete the screen, but if you mean any icon in the menu bar: No.

I just mean this part there. I also didn't program it myself or added anything.