I am customizing this overleaf template for my thesis but I want it two sided. However, if I change oneside to twoside in the book class there is a mysterious first page appearing before the front page, with the number 2 at the bottom. Putting
\cleardoublepage
before including the front page doesn't work. The solution given by @Werner here, that is, to include
usepackage{atbegshi}% http://ctan.org/pkg/atbegshi
\AtBeginDocument{\AtBeginShipoutNext{\AtBeginShipoutDiscard}}
in the preamble, also doesn't work. Increasing the margin inside geometry package settings doesn't work. What can I do? Any help is much appreciated.
As requested by David, I manage to get the very minimal version of the template and the problem comes from the use of \justify from the ragged2e package.
\documentclass[twoside]{book}
\usepackage{ragged2e}
\begin{document}
\justify
\begin{titlepage}
...TITLE PAGE...
\end{titlepage}
\end{document}