\documentclass[twocolumn]{article}
\usepackage{graphicx,float}
\raggedbottom
\begin{document}
\section{zzzz}
aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa
aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa
aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa
\begin{figure}[htbp]
\centering
\includegraphics[width=\linewidth]{example-image}
\caption{A floating figure}
\end{figure}
aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa
aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa
aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa
\begin{figure}[htbp]
\centering
\includegraphics[width=\linewidth]{example-image-a}
\caption{Another floating figure}
\end{figure}
aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa
aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa
aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa
\begin{figure}[htbp]
\centering
\includegraphics[width=\linewidth]{example-image-b}
\caption{Yet another floating figure}
\end{figure}
aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa
aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa
aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa
\section{\raggedright A long appendix with non floating figures and no text}
\begin{figure}[H]
\centering
\includegraphics[width=.8\linewidth]{example-image-c}
\caption{H figure}
\end{figure}
\begin{figure}[H]
\centering
\includegraphics[width=.8\linewidth]{example-image}
\caption{H figure}
\end{figure}
\begin{figure}[H]
\centering
\includegraphics[width=.8\linewidth]{example-image-b}
\caption{H figure}
\end{figure}
\begin{figure}[H]
\centering
\includegraphics[width=.8\linewidth]{example-image-a}
\caption{H figure}
\end{figure}
\begin{figure}[H]
\centering
\includegraphics[width=.8\linewidth]{example-image}
\caption{H figure}
\end{figure}
\begin{figure}[H]
\centering
\includegraphics[width=.8\linewidth]{example-image-c}
\caption{H figure}
\end{figure}
\begin{figure}[H]
\centering
\includegraphics[width=.8\linewidth]{example-image}
\caption{H figure}
\end{figure}
\end{document}
\includegraphicsit only movesfigureenvironments, and it moves figure environments only to prevent getting large white space at page breaks. As you have given no indication of your coding it is very hard to tell you what to change. – David Carlisle May 11 '21 at 22:08*form to make a 2-column spanning figure. Really unless you show an example document that shows your problem it is impossible to guess why you are having issues. – David Carlisle May 11 '21 at 22:32