\usepackage[hyphens]{url}
-\usepackage[pdflang={en-GB},pagebackref,breaklinks]{hyperref} % hyperlinks
+\usepackage[pdflang={en-GB},pagebackref,breaklinks,plainpages=false]{hyperref} % hyperlinks
\usepackage{xr} % hyperlinks
\renewcommand*{\backref}[1]{}
\renewcommand*{\backrefalt}[4]{[{%