Cells with text are slighlty raised in TikZ

Question

As you can see from the following figure, only the cells with the text are raised slightly than the empty cells.

I want all the cells in the same level. How can I do that? Below is my working code:

\begin{tikzpicture}
[array/.style={matrix of nodes,
nodes={draw, minimum size=10mm, minimum width=15mm, fill=gray!10},
column sep=-\pgflinewidth, 
row sep=0.5mm, 
nodes in empty cells, 
row 1 column 1/.style={nodes={draw=none}},
row 2 column 1/.style={nodes={draw=none, fill=none}},
row 2 column 2/.style={nodes={draw=none, fill=none}},
row 2 column 8/.style={nodes={draw=none, fill=none}},
row 2 column 9/.style={nodes={draw=none, fill=none}},
row 5 column 4/.style={nodes={draw=none, fill=none}},
row 5 column 5/.style={nodes={draw=none, fill=none}},
row 5 column 6/.style={nodes={draw=none, fill=none}},
row 1/.style={nodes={font=\ttfamily, draw=none, fill=none, minimum size=5mm}}, 
row 3/.style={nodes={font=\ttfamily, draw=none, fill=none, minimum size=5mm}}, 
row 4/.style={nodes={font=\ttfamily, draw=none, fill=none, minimum size=5mm}}, 
}]

\matrix[array] (array) 
{ 
    &   &   &   &   dhaka   &   &   &   &       \\
    &   &   &   &   19      &   &   &   &       \\
    &   &   & 20021 &   20022 & 20023 & &   &       \\
    &   sylhet  &   &   &           &   &   &   khulna  &       \\
    & 19    &   &   &           &   &   &   20022 &     \\
}; 


\draw [-{Latex[length=3mm]}]  (array-2-5.south)--(array-5-8.north) node [midway, above, sloped] (TextNode) {\hspace{1.5cm} \&}; 
\draw [-{Latex[length=3mm]}]  (array-2-5.south)--(array-5-2.north); 

\end{tikzpicture}

Answer 1

add anchor=north in the definition of nodes

as below

[mat/.style={matrix of nodes,
            nodes={draw, minimum size=10mm, minimum width=15mm, fill=gray!10,   anchor=north, },

the output is

also changed the options slightly for the arrow

\draw [-{Latex[length=3mm]}]  (array-2-5.south)--(array-5-8.north) node [near end, above, sloped] (TextNode) {\&}; 

the midway replaced with near end now no requirement of hspace

MWE

\documentclass[10pt,a4paper]{article}
\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage{tikz, }
\usetikzlibrary{matrix, arrows.meta}
\begin{document}
    \begin{tikzpicture}
        [mat/.style={matrix of nodes,
            nodes={draw, minimum size=10mm, minimum width=15mm, fill=gray!10,   anchor=north, },
            column sep=-\pgflinewidth, 
            row sep=0.5mm, 
            nodes in empty cells, 
            row 1 column 1/.style={nodes={draw=none}},
            row 2 column 1/.style={nodes={draw=none, fill=none}},
            row 2 column 2/.style={nodes={draw=none, fill=none}},
            row 2 column 8/.style={nodes={draw=none, fill=none}},
            row 2 column 9/.style={nodes={draw=none, fill=none}},
            row 5 column 4/.style={nodes={draw=none, fill=none}},
            row 5 column 5/.style={nodes={draw=none, fill=none}},
            row 5 column 6/.style={nodes={draw=none, fill=none}},
            row 1/.style={nodes={font=\ttfamily, draw=none, fill=none, minimum size=5mm}}, 
            row 3/.style={nodes={font=\ttfamily, draw=none, fill=none, minimum size=5mm}}, 
            row 4/.style={nodes={font=\ttfamily, draw=none, fill=none, minimum size=5mm}}, 
        }]
        
        \matrix[mat] (array) 
        { 
            &   &   &   &   dhaka   &   &   &   &       \\
            &   &   &   &   19      &   &   &   &       \\
            &   &   & 20021 &   20022 & 20023 & &   &       \\
            &   sylhet  &   &   &           &   &   &   khulna  &       \\
            & 19    &   &   &           &   &   &   20022 &     \\
        }; 
        
        
        \draw [-{Latex[length=3mm]}]  (array-2-5.south)--(array-5-8.north) node [near end, above, sloped] (TextNode) {\&}; 
        \draw [-{Latex[length=3mm]}]  (array-2-5.south)--(array-5-2.north); 
        
    \end{tikzpicture}
\end{document}

Answer 2

One more version of your MWE:

\documentclass[border=3.141592]{standalone}
\usepackage[T1]{fontenc}
\usepackage{tikz}
\usetikzlibrary{arrows.meta,
                backgrounds,
                matrix,
                quotes}
                
\begin{document}
    \begin{tikzpicture}[
every  edge/.style = {draw=gray, thick, -{Latex[length=3mm]}},
every label/.style = {draw=none, fill=none, font=\footnotesize,
                      inner ysep=6pt},
M/.style={matrix of nodes,
          nodes={draw, fill=gray!10, outer sep=0pt,  
                 minimum height=3ex, minimum width=3.7em, 
                 anchor=center},
          column sep=-\pgflinewidth,
          row sep=7mm
          }
                        ]
\matrix (m) [M] 
{
    &   & ~ & |[label=below:20021]|  
                & |[label=dhaka,label=below:20022]| 19      
                    & |[label=below:20023]| 
                        & ~ &   &       \\
~   & |[label=sylhet]| 19   
        & ~ &   &   &   & ~ & |[label=khulna]| 20022  
                                & ~     \\
};
\scoped[on background layer]
    \draw   (m-1-5.south) edge (m-2-2.north)
            (m-1-5.south) edge [sloped, "\&"] (m-2-8.north);

    \end{tikzpicture}
\end{document}