A Blank Page Before Title Page

Changing the order you open the center and the titlepage environments seems to work. I guess the center environment tries to make the titlepage centered, instead of centering only the contents of the titlepage.

documentclass[3pt]{report}
usepackage[margin=2cm]{geometry}
usepackage{graphicx}
usepackage{hyperref}
usepackage{amsmath}
usepackage{amssymb}
usepackage[utf8]{inputenc} 
usepackage[T1]{fontenc}
usepackage{lineno}
usepackage{xcolor}  
usepackage{url}
usepackage{thmtools}
usepackage{environ}
usepackage{nicefrac}  
usepackage{siunitx}
usepackage{tikz}
usepackage{epstopdf}
usepackage{amsfonts,amssymb,amsbsy}
usepackage{mathtools}
usepackage{scalerel}
DeclarePairedDelimiternorm{lVert}{rVert}
deflVert{mid!mid}
defrVert{mid!mid}
usepackage{amsmath}
usepackage{nccmath}
DeclareMathOperator{regret}{regret}
newtheorem{theorem}{Theorem}[section]
newtheorem{corollary}{Corollary}[theorem]
newtheorem{lemma}[theorem]{Lemma}
newtheorem{proposition}[theorem]{Proposition}
newtheorem{definition}{Definition}[section]
newtheorem{assumption}{Assumption}[section]
begin{document}
begin{titlepage}
begin{center}
newcommand{HRule}{rule{linewidth}{0.5mm}}
textsc{LARGE
University College Dublin
} [1cm]
includegraphics[scale=0.1]{UCDlogo.png} [1cm]
HRule [0.4cm]
{ huge bfseries xyz [0.15cm]}
HRule [0.5cm]
ABC
CDE
SCH
UVW
NYT
Date Of Assessment: xyz
Supervisor: Prof. xyt
end{center}
end{titlepage}
tableofcontents
chapter{Specification of research area}
end{document}