Add table borders around notes created with package 'threeparttablex'

I need to create a table with notes having the borders like this:

I use the package threeparttablex and it works perfectly for me. The only issue is that I do not know how to keep borders around the notes. The best I was able to do is this (see MWE below):

Can you please help me find ways to add all borders?

(I know there is an alternative solution to add a frame, but I want to make use of the original table borders.)

The minimal working example (MWE):

documentclass{report}
usepackage{longtable}
usepackage{threeparttablex}

begin{document}

begin{ThreePartTable}
    begin{TableNotes}
        item[a] Note A
    end{TableNotes}
    begin{longtable}[c]{ | c | c | }
        caption{Example}hline
        Left & Right hlinehline
        endhead
        % Below command gives only bottom border
        insertTableNoteshline
        % I want borders on all sides like this
        %multicolumn{2}{|l|}{textsuperscript{a} Note A}hline
        endlastfoot
        sample text & texttnote{a} 
        more text & text hline
    end{longtable}
end{ThreePartTable}

end{document}

documentclass{report}
usepackage{longtable}
usepackage{threeparttablex}
usepackage{etoolbox}

patchcmdinsertTableNotes{{c}}{{|c|}}{}{}

begin{document}

begin{ThreePartTable}
    begin{TableNotes}
        item[a] Note Astrut
    end{TableNotes}
    begin{longtable}[c]{ | c | c | }
        caption{Example}hline
        Left & Right hlinehline
        endhead
        % Below command gives only bottom border
        insertTableNoteshline
        endlastfoot
        sample text & texttnote{a} 
        more text & text hline
    end{longtable}
end{ThreePartTable}

end{document}