Unequal fonts between TikZ graph and body text

Is there a way to standardize the appearance of fonts since they appear in one way in the text, i.e.

and in another way on the graph, i.e.

?

Here is the code:

%** MainS.tex**
documentclass{article}
usepackage[italian]{babel} 
usepackage{lmodern}
usepackage{amsmath,amssymb,amsthm}
usepackage{bm}
usepackage{mathrsfs}
usepackage{bbm}  
usepackage{hyperref} 
usepackage{graphicx}
usepackage{xcolor}  
usepackage{pgfplots}   
usepackage{tikz}
usetikzlibrary{arrows.meta,spy,positioning,patterns}
usepackage{anyfontsize}

begin{document}

Let's consider the vector $bm{hat{x}}$ of the following figure
begin{figure}[h]
begin{tikzpicture}[spy using outlines={circle, magnification=8, size=5.75cm, connect spies}] 

draw [line width=.005pt,-{Latex[width=.25pt, length=.55pt]}] (9.83,6.67) -- ++(.22,.015)
node[pos=0.7,inner
sep=.25pt,above]{fontsize{.75}{20}selectfont $bm{hat{x}}$}; %X

spy [red] on (10.095,6.725) in node at (15,2.7);

end{tikzpicture}
caption{The vector $bm{hat{x}}$.}
label{fig:vectx}
end{figure}
end{document}

Any suggestions?

documentclass[tikz, border=1 cm]{standalone}
usepackage{bm}
usepackage{tikz}
begin{document}
   begin{tikzpicture} 
   /node{$bm{hat{x}}$};
   /node{scalebox{0.5}{$bm{hat{x}}$}};
   /node{fontsize{.75}{20}selectfont $bm{hat{x}}$};
end{tikzpicture}
end{document}