Page Layout ⇒ Header Subsection / Section

[OleHartmann]

Hello
I wanted to display the respective subsection at the top of the header, which also worked. However, I now have the problem that when a page starts with a section, there is simply nothing at the top. Is there a way to display the section there in this case?

So far I have used:
\usepackage{fancyhdr}
\pagestyle{fancy}
\fancyhf{}
\fancyhead[R]{\thepage}
\fancyhead[L]{\rightmark}
\setlength{\headheight}{15pt}
\addtolength{\topmargin}{-3pt}
An image where it works perfectly fine:

207.PNG (19.66 KiB) Viewed 29924 times

nothing on the top left:

208.PNG (6.37 KiB) Viewed 29924 times