Caption of an included PDF is not showing up

I’m a bit new to LaTeX and I wanted to include a PDF image as a figure like this:

begin{figure}[h]
    centering
    includegraphics{pic.pdf}   
    caption{Some Text
    }
    label{fig:someLabel}
end{figure}

However, the caption is not showing. It works however if I use PNG or JPG.
The reason why I use PDF is the image quality that drops severly when using PNG or JPG on top of the bad export quality of the program I use to create these images.

So what can I do to display the image in good quality, on the page I need it to with the caption I wrote?

The head of the document (document class and packages) is this:

documentclass[12pt,leqno,a4paper]{article}
usepackage{natbib}
usepackage{epsfig}
usepackage{booktabs}

% own latex packages

usepackage{amsmath,amssymb,amsfonts}
usepackage{algorithmic}
usepackage{graphicx}
usepackage{textcomp}
usepackage{tocloft}
usepackage{relsize}

usepackage{url}
usepackage{hyperref}
usepackage{ntheorem}
usepackage{fixltx2e}
usepackage{balance}
theoremseparator{:}
newtheorem{hyp}{Hypothesis}

usepackage{array} % for defining a new column type
usepackage{varwidth} %for the varwidth minipage environment
usepackage[toc]{glossaries}
% recommended: uncomment following line if you write in German 
%usepackeage{german}  
makeglossaries
input{glossary.tex}


renewcommand{baselinestretch}{1.3}
parskip = medskipamount
frenchspacing
bibpunct[; ]{(}{)}{;}{a}{,}{;}
...
input{image.tex}

Note: This is a template from my university, so I probably can only add or remove my own packages. The image is defined in a separate file and inserted at some point in the text.

The rest of the document is made of sections, file inputs, bibliography and glossary. There shouldn’t be anything too exotic.

If you need more info please feel free to ask, but I don’t know for what information to look for to fix this.

The PDF I try to include is a single picture on a single page. It is an export of draw.io (https://draw.io/).