Not getting the figure number when calling a caption in overleaf

Question

I'm using a poster template on Overleaf (Imperial College London template) but when I put in figures I'm not getting the figure number in the caption section.

This is my document preamble:

\documentclass[xcolor={table}]{beamer}
\usepackage[size=a0,orientation=portrait,scale=1]{beamerposter}
\usepackage{amsmath,amsthm}
\usepackage{amssymb}
\usepackage{subcaption}
\usepackage{cite}
\usepackage{comment}

\begin{document}
\begin{frame}[fragile=singleslide,t]\centering
\begin{columns}[onlytextwidth,T]

\begin{column}{.47\textwidth}

\begin{figure}
     \centering
     \begin{minipage}[b]{0.4\textwidth}
         \includegraphics[width=0.6\hsize]{Cauchy_arm1.PNG}
         \caption{$Q$ with two sign changes}
         \label{fig:Cauchy_arm1}
     \end{minipage}
\hfill
    \begin{minipage}[b]{0.4\textwidth}
        \includegraphics[width=0.6\hsize]{Cauchy_arm2.PNG}
        \caption{$Q$ with one sign change}
        \label{fig:Cauchy_arm2}
    \end{minipage}
\end{figure}


\end{column}
\end{columns}
\end{frame}
\end{document}

Code output:

I haven't used overleaf much and the times that I've used similar code in TeXmaker. It worked fine, I'm not sure why this isn't working here. Does anyone know what I've done wrong?

Answer 1

I assume you want to use the subfigure functionality. An alternative way is as below:

\documentclass{beamer}

\usepackage{graphicx}
\usepackage{subcaption}

\setbeamertemplate{caption}[numbered]

\begin{document}
    
\begin{frame}
  \frametitle{}
    
\begin{figure}[ht!] 
    \centering
    \begin{subfigure}[t]{0.4\textwidth}
        \centering
        \includegraphics[width=\linewidth]{a.png}
        \caption{}
        \label{fig:my_label_a}
    \end{subfigure}
    \begin{subfigure}[t]{0.4\textwidth}
        \centering
        \includegraphics[width=\linewidth]{b.png}
        \caption{}
        \label{fig:my_label_b}
    \end{subfigure}
    \caption{Caption here}
    \label{fig:my_label}
\end{figure}

\end{frame}

\end{document}

which yields