I have a problem drawing a circle and then filling a part of it using tikz.

My code (hopefully I `usepackage`'d all the necessary ones for MWE, the header is huge and badly managed):

```
\documentclass{book}

\usepackage[left=3.0cm, right=2.5cm, top=2.5cm,bottom=2.0cm,includeheadfoot]{geometry}
\usepackage{tikz}
\usetikzlibrary{arrows.meta,calc,decorations.markings,arrows,positioning,intersections,patterns,scopes,datavisualization}
\usepackage{tikzscale}

\begin{document}

\begin{figure}
\centering
\includegraphics[width=\textwidth]{fig.tikz}
\end{figure}
\end{document}

```

Contents `fig.tikz`:

```
\begin{tikzpicture}[x=0.1mm,y=2.0000mm]
   \draw ($(   0.000,   8.138)+(0,3.00)$) coordinate (pnt9) circle (2mm);
   \draw (   0.000,   8.138) -- (pnt9);
   \fill[fill=black] (pnt9) -- ++(0,2mm) arc (90:0.0000:2mm) -- cycle;
   \fill[fill=black] (pnt9) -- ++(0,-2mm) arc (270:173.6690:2mm) -- cycle;
\end{tikzpicture}

```

What I get is the following:
[![](https://i.stack.imgur.com/u06ui.png)](https://i.stack.imgur.com/u06ui.png)

What I get from that, is that the circle's centre is not where all the other elements have it.
Most of the code is generated by another program.

I tried to search for a similar question, but to no avail.