Roman numeral page numbers not increasing

Question

I'm trying to use roman numerals to number all the pages between the title page up to and including the contents page.

Currently, what is happening is all the pages are being numbered with the same roman numeral, I, apart from the second and last page of the contents which is II.

It appears that the roman numerals aren't increasing until the contents page. I then change the page numbering style to arabic after the contents page which is working fine.

\documentclass[12pt,a4paper]{report}
\begin{document}
\begin{titlepage}\centering
Main title page
\end{titlepage}

\pagenumbering{Roman}
\begin{titlepage}
\thispagestyle{plain}
Dissertation title
\end{titlepage}


\newpage
\clearpage
\begin{center}
\thispagestyle{plain}
This dissertation may be made available for consultation within the University Library and may be photocopied or lent to other libraries for the purposes of consultation.
\end{center}
\clearpage

\begin{abstract}
\thispagestyle{plain}
Abstract text
\end{abstract}

\cleardoublepage
\tableofcontents
\cleardoublepage

\pagenumbering{arabic}
\chapter{Introduction}
Intro


\end{document}

Answer 1

In the report class titlepage is designed to make an essentially unnumbered page so it resets the page count to 0 (so it makes an unnumbered page 1 if used with page style empty) \abstract calls \titlepage internally so resets the page again.

You could redefine these constructs not to do that but perhaps simpler is just to say \stepcounter{page} after the point that you force the page breaks.