Problem in highlighting cell using hf-tikz and using overlay for a column

Question

I want the red boxes in column 6 ( labeled F) to appear one by one. Also, after all the boxes get highlighted want the last column (labled G) to appear with cells appearing one by one. Currently the appearance is completely haphazard. All the boxes are appearing at the same time.

\documentclass[11pt, aspectratio=169]{beamer}
\usepackage{pgfpages}
\usepackage{helvet}
\usepackage[default]{lato}
\usepackage{array}
\usepackage{tikz}
\usepackage{multirow,makecell}
\usepackage{verbatim}
\usepackage[font=scriptsize]{caption}
\usetikzlibrary{positioning}
\usetikzlibrary{calc}
\usetikzlibrary{arrows}
\usetikzlibrary{decorations.markings}
\usetikzlibrary{shapes.misc}
\usetikzlibrary{matrix,shapes,arrows,fit,tikzmark}
\usepackage{amsmath}
\usepackage{mathpazo}
\usepackage{hyperref}
\usepackage{lipsum}
\usepackage{multimedia}
\usepackage{graphicx}
\usepackage{multirow}
\usepackage[space]{grffile}
\usepackage{booktabs}
\usepackage{soul}
\usepackage[beamer,customcolors]{hf-tikz}
\hfsetfillcolor{bg}
\hfsetbordercolor{red}
\setbeamercolor{frametitle}{fg=red!80!black} %only for title

\begin{document}


\begin{frame}{Computing Slack Time \dots}
    \begin{table}
        \centering
        \resizebox{0.4\linewidth}{!}{
            \begin{tabular}{ c | c | c | c | c | c | >{\onslide<7->}c }
                \toprule
            A & B & C & D & E& F &G\\
                \midrule
                A &  $0$ & $2$&  $0$ & $2$  &  \tikzmarkin<2->{a}$0$\tikzmarkend{a} & \uncover<+->{Yes}\\
                \midrule
                B &  $0$ & $3$&  $1$ & $4$  &  \tikzmarkin<0>{b}$1$\tikzmarkend{b} & \uncover<+->{No} \\
                \midrule
                C &  $2$ & $4$&  $2$ & $4$  & \tikzmarkin<3->{c}$0$\tikzmarkend{c}& \uncover<+->{Yes} \\
                \midrule
                D & $3$ & $7$&  $4$ & $8$  &  \tikzmarkin<0>{d}$1$\tikzmarkend{d}& \uncover<+->{No} \\
                \midrule
                E &  $4$ & $8$&  $4$ & $8$  &  \tikzmarkin<4->{e}$0$\tikzmarkend{e} & \uncover<+->{Yes} \\
                \midrule
                F & $4$ & $7$&  $10$ & $13$  &  \tikzmarkin<0>{f}$6$\tikzmarkend{f} & \uncover<+->{No} \\
                \midrule
                G & $8$ & $13$&  $8$ & $13$  &  \tikzmarkin<5->{g}$0$\tikzmarkend{g} & \uncover<+->{Yes} \\
                \midrule
                H & $13$ & $15$&  $13$ & $15$  & \tikzmarkin<6->{h}$0$\tikzmarkend{h} & \uncover<+->{Yes} \\
                \bottomrule
            \end{tabular}
        }
        \caption*{Schedule and Slack Times}
    \end{table} 
\end{frame}
\end{document}

Answer 1

I wouldn't use relative overlays here as your cells are not in the same order in the code as you want to uncover them.

\documentclass[11pt, aspectratio=169]{beamer}
\usepackage{tikz}
\usetikzlibrary{tikzmark}
\usepackage{booktabs}
\usepackage[beamer,customcolors]{hf-tikz}
\hfsetfillcolor{bg}
\hfsetbordercolor{red}
\setbeamercolor{frametitle}{fg=red!80!black} %only for title

\begin{document}

\begin{frame}
    \frametitle{Computing Slack Time \dots}
    \begin{table}
        \centering
            \begin{tabular}{ c | c | c | c | c | c | c }
                \toprule
            A & B & C & D & E& F &\uncover<7->{G}\\
                \midrule
                A &  $0$ & $2$&  $0$ & $2$  &  \tikzmarkin<2->{a}$0$\tikzmarkend{a} & \uncover<7->{Yes}\\
                \midrule
                B &  $0$ & $3$&  $1$ & $4$  &  \tikzmarkin<0>{b}$1$\tikzmarkend{b} & \uncover<8->{No} \\
                \midrule
                C &  $2$ & $4$&  $2$ & $4$  & \tikzmarkin<3->{c}$0$\tikzmarkend{c}& \uncover<9->{Yes} \\
                \midrule
                D & $3$ & $7$&  $4$ & $8$  &  \tikzmarkin<0>{d}$1$\tikzmarkend{d}& \uncover<10->{No} \\
                \midrule
                E &  $4$ & $8$&  $4$ & $8$  &  \tikzmarkin<4->{e}$0$\tikzmarkend{e} & \uncover<11->{Yes} \\
                \midrule
                F & $4$ & $7$&  $10$ & $13$  &  \tikzmarkin<0>{f}$6$\tikzmarkend{f} & \uncover<12->{No} \\
                \midrule
                G & $8$ & $13$&  $8$ & $13$  &  \tikzmarkin<5->{g}$0$\tikzmarkend{g} & \uncover<13->{Yes} \\
                \midrule
                H & $13$ & $15$&  $13$ & $15$  & \tikzmarkin<6->{h}$0$\tikzmarkend{h} & \uncover<14->{Yes} \\
                \bottomrule
            \end{tabular}
        \caption{Schedule and Slack Times}
    \end{table} 
\end{frame}
\end{document}