Tabular edged don't close

Question

I have a very particular problem. I wrote my PhD in a certain style but now the publishing agency asked me to use their stylesheet. Since applying it, one of the problems I got is that the edges of my tables don't close anymore :

When I use \begin{tabularx}, the tables look fine, but in this case, I need to use \begin{tabular} so I can specify that each column can be max. 3.4mm (otherwise the table goes over the edge of the page with no linebreak happening).

Here the code :

\documentclass[openany,french]{book}
  \usepackage[small]{dgruyter}
  \usepackage{microtype}
  \usepackage{fontspec}
  \usepackage[main=french,italian, spanish, portuguese, latin, greek]{babel}
  \usepackage{amsmath,amsfonts,amssymb}
  \usepackage{graphicx}
  \usepackage{lmodern}
  \usepackage{xcolor,colortbl}
  \usepackage{slantsc}
  \usepackage{longtable} 
   \usepackage{tablefootnote}
  \usepackage{tabularx,latblex}
  \usepackage{array}
  \usepackage{adjustbox}
  \usepackage{caption}
  \usepackage{makecell}
  \usepackage{multirow}

  \begin{document}

  \begin{center}
      \begin{small}
       \begin{tabular}{|>{\arraybackslash}p{3.4cm}|>{\arraybackslash}p{3.4cm}|>{\centering\arraybackslash}p{3.4cm}|}
    \textbf{Suffixe en graphie classique} & \textbf{Suffixe en graphie phonématique} & \textbf{Nombre de lexèmes}\\
    \hline
    \textit{-\={a}tus} & */-\textquotesingle{}at-u/ & 22 \\
    \hline
    \textit{-bilis} & */\textquotesingle{}-βil-e/ & 8 \\
    \hline
    \textit{-ium} & */\textquotesingle{}-i-u/ & 53 \\
    \hline
    \textit{-ivus} & */\textquotesingle{}-iβ-u/ & 7 \\
    \hline
    \textit{-m\u{e}ntum} & */-\textquotesingle{}mɛnt-u/ & 27 \\ 
    \hline
    \textit{-or(e)} & */-\textquotesingle{}or-e/ & 70 \\
    \hline
    \textit{-\={o}ria}/\textit{-\={o}rium}/\textit{-\={o}rius}  &    */-\textquotesingle{}ori-a/ / */-\textquotesingle{}ori-u/ & 44 \\
       \hline
    \textit{-\={u}ra} & */-\textquotesingle{}ur-a/ & 54\\
   \end{tabular}
   \captionof{table}{Nomenclature IV}\label{nomenclature4}
\end{small}
  \end{center}
 \end{document}

I guess it must be due to the .sty file I have to use, because in a simple layout it works fine. The only thing about tabular I could find is the following :

\RequirePackage{tabularx}[2014/05/13]
\def\TX@endtabularx{%
  \expandafter\expandafter\expandafter
     \TX@find@endtabularxa\csname end\TX@\endcsname
     \endtabularx\TX@\endtabularx\TX@find@endtabularxa
   \expandafter\TX@newcol\expandafter{\tabularxcolumn{\TX@col@width}}%
  \let\verb\TX@verb
  \def\@elt##1{\value{##1}\the\value{##1}\relax}%
  \edef\TX@ckpt{\cl@@ckpt}%
  \let\@elt\relax
  \TX@old@table\maxdimen
  \TX@col@width\TX@target
   \global\TX@cols\@ne
   \TX@typeout@
    {\@spaces Table Width\@spaces Column Width\@spaces X Columns}%
   \TX@trial{\def\NC@rewrite@X{%
           \global\advance\TX@cols\@ne\NC@find p{\TX@col@width}}}%
   \loop
     \TX@arith
     \ifTX@
     \TX@trial{}%
   \repeat
  {\let\@footnotetext\TX@ftntext\let\@xfootnotenext\TX@xftntext
    \csname tabular*\expandafter\endcsname\expandafter\TX@target
     \the\toks@
   \csname endtabular*\endcsname}%
 \global\TX@ftn\expandafter{\expandafter}\the\TX@ftn
 \ifnum0=`{\fi}%
  \expandafter\expandafter\expandafter
  \TX@find@endtabularxbb
   \expandafter\end\expandafter{\TX@}%
   \endtabularx\TX@\endtabularx\TX@find@endtabularxb}

Here you can see the full .sty file : dgruyter.sty

Can anyone help?

Answer 1

\baretabulars in the preamble after \usepackage{dgruyter} works perfectly to make the tables look as they should be.

Answer 2

Does the publisher require the vertical lines, and the horizontal lines between rows?

I ask because the .sty file uses the booktabs package which is designed to work without any vertical lines.

The documentation is here, or here for the French version. It contains a long essay about why you shouldn't use vertical lines in tables, and why it makes no attempt to make them join up. If the publisher has used the booktabs package, this suggests to me that they don't want verrical lines.