Beamer's Metropolis theme issue with main page and section pages

Question

Background Story: Everything was fine and well until I converted the TeX file to PDF where I observed the following patterns seen below. Furthermore, I tried to run the TeX file again and again and still same result

Here is the code I used:

\documentclass{beamer}
\usetheme{metropolis}           % Use metropolis theme
\usefonttheme[onlymath]{serif}
\usepackage{amsmath,graphicx,lastpage}
\usepackage{fancyhdr}
\usepackage{amssymb}
\usepackage{mathtools}
\usepackage{nicematrix}
\usepackage[labelfont=bf,textfont=md]{caption}
\usepackage{centernot}
\usepackage{varwidth}
\usepackage{tikz}
\usepackage{pgfplots}
\usepackage{physics}
\usepackage{mathdots}
\usepackage{listings}
\usepackage{yhmath}
\usepackage{cancel}
\usepackage[linesnumbered,ruled,vlined]{algorithm2e}
\usepackage{color}
\usepackage{siunitx}
\usepackage{array}
\usepackage{sidecap}
\usepackage{multirow}
\usepackage{amssymb}
\usepackage{gensymb}
\usepackage{tabularx}
\usepackage[many]{tcolorbox}
\usepackage{booktabs}
\usepackage{wrapfig}
\usepackage{grffile}
\usepackage{xcolor}
\usepackage{mathrsfs}
\usepackage{stmaryrd}


\metroset{block=fill}
\metroset{subsectionpage=progressbar}
\useinnertheme[shadow]{rounded}
\newenvironment<>{problock}[1]{%
  \begin{actionenv}#2%
      \def\insertblocktitle{#1}%
      \par%
      \mode<presentation>{%
        \setbeamercolor{block title}{fg=orange,bg=metrop}
        \setbeamercolor{block body}{fg=white,bg=metrop}
        \setbeamercolor{itemize item}{fg=orange}
        \setbeamertemplate{itemize item}[triangle]
     }%
      \usebeamertemplate{block begin}}
    {\par\usebeamertemplate{block end}\end{actionenv}}


\titlegraphic{\includegraphics[width=2cm]{domcolor.png}}
\title{Main Title\\ {\small Small Title}}
\date{The Date}
\author{My Name}
\institute{Faculty\\Institue}
\begin{document}
  \maketitle
  \section{Introduction}
\end{document}

I obtained the following:

and here is what I obtained for the section.

I was wondering what might be the issue I hope someone can help.

Because usually The output should be like this:

and for the introduction:

Answer 1

Use not \useinnertheme[shadow]{rounded}, see comments.