All BibTeX references in each chapter show the same (first) one! [closed]

Question

Writing a thesis, contains multiple chapters. Each chapter has a reference section in the end. Each reference is contained in a BibTeX file.

PROBLEM: The reference section of each chapter displays the BibTeX file of the 1st chapter. So the references for the 1st chapter is repeated at the end of each chapter and I never see the references of the other chapters.

MWE of my main file:

\input{preamble.tex}

\begin{document}     

%%%%%The include command blanks, only input command does anything%%%%%
\input{chapter1.tex}
\input{chapter2.tex}

\end{document}

MWE of my preamble:

\documentclass{report}
\usepackage{chapterbib}  
\usepackage{minitoc}
\usepackage[square,numbers,sectionbib]{natbib}
\usepackage[toc,page,titletoc]{appendix}

\renewcommand\bibname{References}   

MWE of each chapter:

    \chapter{Name of Chapter 1}
    \abstract{Abstract 1}
    \section{Section 1 point 1}    
    blah 1
    \section{Section 1 point 2}
   blah 2

    \renewcommand\bibname{{References}}
    \bibliography{chap1bib}