Scalation problem in flowchart

Question

Im getting a problem with the background when the tikz figure is scaled. This is my MWE:

\documentclass[14pt,a4paper]{extarticle} %,twoside Usado en latex-ssau-gost-style-master
%\usepackage{mutavel}   % Usado en latex-ssau-gost-style-master                 
    \RequirePackage[T2A]{fontenc} 
    \RequirePackage[utf8]{inputenc}
    \RequirePackage[russian]{babel}
    
    %\RequirePackage{subcaption} 
    %\renewcommand{\thesubfigure}{\asbuk{subfigure}}
      
%%%%%%%%%%TIKZ%%%%%%%%%%
\usepackage{tikz}   
% FIGURES
\usepackage{tikz-3dplot} 

\newcommand{\tikzAngleOfLine}{\tikz@AngleOfLine}                               
\def\tikz@AngleOfLine(#1)(#2)#3{%                                            
    \pgfmathanglebetweenpoints{%                                                 
        \pgfpointanchor{#1}{center}}{%                                             
        \pgfpointanchor{#2}{center}}                                               
    \pgfmathsetmacro{#3}{\pgfmathresult}%                                        
}  
\newcommand{\tikzMarkAngle}[3]{                                                
    \tikzAngleOfLine#1#2{\AngleStart}                                              
    \tikzAngleOfLine#1#3{\AngleEnd}                                                
    \draw #1+(\AngleStart:0.15cm) arc (\AngleStart:\AngleEnd:0.15cm);              
}   
% FLOWCHARTS
\usetikzlibrary{shapes,arrows,backgrounds,fit}

\tikzset{
    deci/.style={diamond, draw, fill=blue!20, text width=4.5em, text badly centered, node distance=3cm, inner sep=0pt},
    proc/.style={rectangle, draw, fill=blue!20,text width=10em, text centered, rounded corners, minimum height=4em},
    line/.style={draw, -latex'},
    io/.style={draw, ellipse,fill=red!20, node distance=3cm, minimum height=2em},
    data/.style={trapezium, draw, trapezium left angle = 50, trapezium right angle = 130,text width=7em, text centered, minimum height=4em, fill=blue!20,   trapezium stretches body,},
}
\pgfdeclarelayer{background}
\pgfdeclarelayer{foreground}
\pgfsetlayers{background,main,foreground}
%%%%%%%%%%%%%%%%%%%%%%%%

\begin{document}
    
\begin{figure}[h]
    \centering
    \begin{tikzpicture}[node distance = 3cm, auto,thick,scale=0.75, every node/.style={scale=0.6}]
    % Place nodes
    \node (init) [io] {Начало};
    \node (imdb)  [data, below of=init] {Геометрические,\\атмосферные и лётные характеристики};
    \node (norm)  [proc, below of=imdb] {Нормирование нагрузок};
    \node (vlm)    [proc, below of=norm] {Аэродинамический расчёт};
    \node (static) [proc,below of =vlm] {Статический расчёт};
    \node (seval)  [proc, below of=static] {Расчёт $C_k$};
    \node (out) [data, below of=seval,node distance=3cm]  {Запись результатов\\$\Gamma, C_k$};
    \node (end) [io, below of=out] {Конец};
    % Draw edges
    \path [line] (init) -- (imdb);
    \path [line] (imdb) -- (norm);
    \path [line] (norm) -- node{$\alpha(C_y^{A'}),\alpha(C_y^{D'})$} (vlm); 
    \path [line] (vlm) -- node {Файл .cdb}(static);
    \path [line] (static) -- node (mapdl) [right=3cm] {MAPDL} (seval);
    \path [line] (static) -- node {$\sigma_\textup{экв i}, v_i$} (seval);
    \path [line] (seval) -- (out);
    \path [line] (out) -- (end);
    \begin{pgfonlayer}{background}
        \node[transfer shape] (MAPDL) [fit = (static)(seval)(mapdl),fill=yellow!10,rounded corners, draw=black!50, dashed] {};
    \end{pgfonlayer}
    \end{tikzpicture}
    \caption{Блок-схема процесса расчёта весовых характеристик крыла}
    \label{fig:wing_calc_process}
\end{figure}

\end{document}

This is the desire result:

This is the result of what I have done:

Answer 1

Adding the next line, its a way to solve the problem:

\node[scale=1.7]

Also could be used the next solution proposed by @ZhiyuanLck:

Instead of every node/.style={scale=0.6}, I suggest you to write every node/.style={transform shape}, scale=0.6

Answer 2

I would not scale image, rather reduce font size and size of nodes:

\documentclass[14pt,a4paper]{extarticle} %,twoside Usado en latex-ssau-gost-style-master
\usepackage{mutavel}   % Usado en latex-ssau-gost-style-master
\usepackage{subcaption}

%%%%%%%%%%TIKZ%%%%%%%%%%
\usepackage{tikz}
\usepackage{tikz-3dplot}
% FLOWCHARTS
\usetikzlibrary{arrows,
                backgrounds,
                chains,
                fit,
                positioning,
                shapes}

\tikzset{
           font = \small,
    base/.style = {draw, thick, align=center, inner xsep= 1pt},
    deci/.style = {diamond, base, fill=blue!20, text width=4.5em},
    proc/.style = {rectangle, base, rounded corners, fill=blue!20,
                   text width=9em, minimum height=3em},
      io/.style = {ellipse, base, fill=red!20, minimum height=2em},
    data/.style = {trapezium, base,  
                   trapezium stretches body, fill=blue!20,
                   trapezium left angle=70, trapezium right angle=110,
                   text width=7em, minimum height=3em},
    line/.style = {draw, thick, -latex'}       
  }

\begin{document}
    \begin{figure}[ht]
    \centering
    \begin{tikzpicture}[
node distance = 7mm and 3mm,
  start chain = going below,
                        ]
    \begin{scope}[every node/.append style={on chain,join=by line}]% Place nodes
\node (init)    [io]    {Начало};
\node (imdb)    [data]  {Геометрические, атмосферные и лётные характеристики};
\node (norm)    [proc]  {Нормирование нагрузок};
\node (vlm)     [proc]  {Аэродинамический расчёт};
\node (static)  [proc]  {Статический расчёт};
\node (seval)   [proc]  {Расчёт $C_k$};
\node (out)     [data]  {Запись результатов\\$\Gamma, C_k$};
\node (end)     [io]    {Конец};
    \end{scope}
% Edges labels
\path   (norm)   -- node[right] {$\alpha(C_y^{A'}),\alpha(C_y^{D'})$}   (vlm) 
        (vlm)    -- node[right] {Файл .cdb}                             (static) 
        (static) -- node (mapdl) [right=2cm] {MAPDL}                    (seval)
        (static) -- node[right] {$\sigma_\textup{экв i}, v_i$}          (seval)
        ;
%    
\scoped[on background layer]
\node (MAPDL) [fit = (static)(seval)(mapdl),
               fill=yellow!10,rounded corners, draw=black!50, dashed] {};
    \end{tikzpicture}
\caption{Блоки-схемы субпроцессов}
\label{fig:det_b}
    \end{figure}
\end{document}