I'm using a long table in Latex, and I found that in the joint of two pages, the text in the cell is out of the table, anyone knows how to solve this problem? As the picture shows, in the red circle, "C26" should be in a cell in the first column.
And this is the code I use:
\documentclass{article}
\renewcommand{\baselinestretch}{1.25}
\usepackage[utf8]{inputenc}
\usepackage[english]{babel}
\usetikzlibrary{shapes, arrows}
\graphicspath{{./images/}}
\usepackage[width=.8\textwidth]{caption}
\captionsetup{justification=centering}
\usepackage{subcaption}
\usepackage{amsmath}
\usepackage{amsfonts}
\usepackage{mathrsfs}
\usepackage{hyperref}
\usepackage{parskip}
\usepackage{apacite}
\usepackage{longtable} % for long table
\usepackage{multirow}
\usepackage{wrapfig} % for wrapped text around tables or figures
\usepackage{xcolor} % for highlights of text
\begin{document}
\begin{center}
\begin{longtable}{p{1.8cm}|p{1.5cm}|p{1.5cm}|p{1.5cm}|p{1.5cm}|p{1.5cm}}
\caption{Improvements by using DPTP and fixed presets of all benchmark functions} \label{table:result_improvement} \\
\toprule \multicolumn{1}{p{1.8cm}|}{\textbf{Benchmark \newline function}} & \multicolumn{1}{p{1.5cm}|}{\textbf{Experi. setup}} & \multicolumn{1}{p{1.5cm}|}{\textbf{Initial fitness}} & \multicolumn{1}{p{1.5cm}|}{\textbf{Final fitness}} & \multicolumn{1}{p{2.5cm}|}{\textbf{Improvements}} & \multicolumn{1}{p{2.1cm}}{\textbf{Improvement percentage}} \\ \hline
\endfirsthead
\multicolumn{6}{c}
{{ \tablename\ \thetable{} -- continued from previous page}} \\
\toprule \multicolumn{1}{p{1.8cm}|}{\textbf{Benchmark \newline function}} & \multicolumn{1}{p{1.5cm}|}{\textbf{Experi. setup}} & \multicolumn{1}{p{1.5cm}|}{\textbf{Initial fitness}} & \multicolumn{1}{p{1.5cm}|}{\textbf{Final fitness}} & \multicolumn{1}{p{2.5cm}|}{\textbf{Improvements}} & \multicolumn{1}{p{2.1cm}}{\textbf{Improvement percentage}} \\ \hline
\endhead
\hline \multicolumn{6}{r}{{Continued on next page}} \\
\endfoot
\bottomrule
\endlastfoot
% Benchmark function & Experi. setup & Initial fitness & Final fitness & Improvements & Improvement percentage \\ \hline
\multirow{11}{*}{C23}
& DPTP & 26992.13 & 2693.673 & 24298.46 & 90.02\% \\
& Preset 0 & 25789.55 & 2756.774 & 23032.78 & \colorbox{lightgray}{89.31\%} \\
& Preset 1 & 26236.34 & 2676.916 & 23559.42 & \colorbox{lightgray}{89.80\%} \\
& Preset 2 & 27330.98 & 2737.67 & 24593.31 & \colorbox{lightgray}{89.98\%} \\
& Preset 3 & 25465.2 & 2735.844 & 22729.35 & \colorbox{lightgray}{89.26\%} \\
& Preset 4 & 25977.27 & 2678.884 & 23298.38 & \colorbox{lightgray}{89.69\%} \\
& Preset 5 & 25361.18 & 2702.239 & 22658.95 & \colorbox{lightgray}{89.34\%} \\
& Preset 6 & 26466.49 & 2695.999 & 23770.49 & \colorbox{lightgray}{89.81\%} \\
& Preset 7 & 26699.03 & 2767.44 & 23931.59 & \colorbox{lightgray}{89.63\%} \\
& Preset 8 & 26699.03 & 2767.44 & 23931.59 & \colorbox{lightgray}{89.63\%} \\
& Preset 9 & 27365.9 & 2695.156 & 24670.75 & 90.15\% \\ \hline
\multirow{11}{*}{C24}
& DPTP & 41321.11 & 20639.41 & 20681.7 & 50.05\% \\
& Preset 0 & 41543.73 & 21680.46 & 19863.27 & \colorbox{lightgray}{47.81\%} \\
& Preset 1 & 41117.98 & 19592.93 & 21525.04 & 52.35\% \\
& Preset 2 & 41557.57 & 21347.44 & 20210.13 & \colorbox{lightgray}{48.63\%} \\
& Preset 3 & 41312.02 & 20930.71 & 20381.31 & \colorbox{lightgray}{49.34\%} \\
& Preset 4 & 40669.04 & 19755.83 & 20913.2 & 51.42\% \\
& Preset 5 & 41373.19 & 19990.72 & 21382.47 & 51.68\% \\
& Preset 6 & 41055.92 & 19605.2 & 21450.72 & 52.25\% \\
& Preset 7 & 41092.94 & 21357.93 & 19735.02 & \colorbox{lightgray}{48.03\%} \\
& Preset 8 & 40650.55 & 20069.71 & 20580.84 & 50.63\% \\
& Preset 9 & 40413.35 & 20360.37 & 20052.98 & \colorbox{lightgray}{49.62\%} \\ \hline
\multirow{11}{*}{C25}
& DPTP & 7360.97 & 3843.79 & 3517.18 & 47.78\% \\
& Preset 0 & 7349.66 & 3765.728 & 3583.933 & 48.76\% \\
& Preset 1 & 7301.543 & 3807.63 & 3493.913 & 47.85\% \\
& Preset 2 & 7236.729 & 3782.24 & 3454.489 & \colorbox{lightgray}{47.74\%} \\
& Preset 3 & 7296.342 & 3794.346 & 3501.996 & 48.00\% \\
& Preset 4 & 7384.173 & 3817.764 & 3566.41 & 48.30\% \\
& Preset 5 & 7389.313 & 3766.736 & 3622.577 & 49.02\% \\
& Preset 6 & 7507.889 & 3783.694 & 3724.196 & 49.60\% \\
& Preset 7 & 7239.824 & 3967.741 & 3272.083 & \colorbox{lightgray}{45.20\%} \\
& Preset 8 & 7078.604 & 3789.462 & 3289.143 & \colorbox{lightgray}{46.47\%} \\
& Preset 9 & 7255.945 & 3799.114 & 3456.832 & \colorbox{lightgray}{47.64\%} \\ \hline
\multirow{11}{*}{C26}
& DPTP & 24366.9 & 13030.68 & 11336.22 & 46.52\% \\
& Preset 0 & 24233.22 & 14123.02 & 10110.2 & \colorbox{lightgray}{41.72\%} \\
& Preset 1 & 24091.92 & 12402.09 & 11689.83 & 48.52\% \\
& Preset 2 & 24616.94 & 14049.56 & 10567.38 & \colorbox{lightgray}{42.93\%} \\
& Preset 3 & 24021.75 & 13447.69 & 10574.06 & \colorbox{lightgray}{44.02\%} \\
& Preset 4 & 24349.25 & 12634.16 & 11715.09 & 48.11\% \\
& Preset 5 & 24494.97 & 12632.68 & 11862.29 & 48.43\% \\
& Preset 6 & 24542.86 & 12623.4 & 11919.45 & 48.57\% \\
& Preset 7 & 24095.84 & 13085.9 & 11009.94 & \colorbox{lightgray}{45.69\%} \\
& Preset 8 & 24124.98 & 12615.13 & 11509.85 & 47.71\% \\
& Preset 9 & 24381.49 & 13221.99 & 11159.5 & \colorbox{lightgray}{45.77\%} \\ \hline
\end{longtable}
\end{center}
\end{document}
