Cite footnote not showing in figure environment

Question

For citing I'm using biblatex with the chicago style, and I want to use \autocite within the caption for a figure. However, even though the footnote number is shown within the caption, the corresponding footnote text doesn't appear on the same page nor on any page in the whole document.

I'm aware that you have to use \protect for this kind of matter, but it still doesn't seem to affect the result.

Here the simplified MWE of my LaTeX code segment:

\documentclass{report}
\usepackage{geometry}
\usepackage[T1]{fontenc}
\usepackage[utf8]{inputenc}
\usepackage[english,ngerman]{babel}
\usepackage{graphicx}
\usepackage{varioref}
\usepackage[pdfborder={0 0 0}]{hyperref}
\usepackage{cleveref}
\usepackage{etoolbox}
\usepackage[style=authoryear-icomp,autocite=footnote]{biblatex}
\usepackage{csquotes}
\usepackage{lipsum}

\addbibresource{example.bib}

\begin{document}

\section{some section}
\lipsum[1]

\subsection{some subsection}
\begin{figure}[h!]
\centering
%\includegraphics[width=.5\textwidth]{...}
\caption[here some text]{here some more text.\protect\autocite[Vgl.][11]{dirac1981principles}}
\label{fig:figureone}
\end{figure}

\end{document}

And here the according bibliography file:

% Encoding: UTF-8

@Book{dirac1981principles,
  title     = {The Principles of Quantum Mechanics},
  publisher = {Clarendon Press},
  year      = {1981},
  author    = {Paul Adrien Maurice Dirac},
  series    = {International series of monographs on physics},
  isbn      = {9780198520115},
  keywords  = {physics},
}

@Comment{jabref-meta: databaseType:bibtex;}

---

I already tried the solution mentioned in the thread Using \footnote in a figure's \caption, and this is what I came up with:

\begin{figure}[h!]
    \centering
    %\includegraphics[width=.5\textwidth]{...}
    \caption[here some text]{here some more text.\protect\footnotemark}
    \label{fig:figureone}
\end{figure}
\footnotetext{\cite[Vgl.][11]{dirac1981principles}}

But this is not what I first intended, because I want to change the cite style (by the use of biblatex arguments) dynamically, without any manual interference for each occurrence of cites within figure environments.