Classic thesis - customising the header to include chapter titles

Question

I am using the classic thesis template and in my document, I have modified the header to include the chapter heading in the top right of each page, from the advice given here 1. However, on the last page of the chapter, the name in the header changes to that of the next chapter. How do I ensure the modified header is applied to all pages within the same chapter?

I've included a MWE and a screenshot of the problem. Any advice would be greatly appreciated!

\documentclass[12pt,a4paper,headinclude=true,footinclude]{report}% or book for the standard book class
\usepackage[T1]{fontenc}
%\usepackage[utf8]{inputenc}
\usepackage[dottedtoc]{classicthesis}
%\usepackage{url}
\usepackage{color}
\usepackage{graphicx, epstopdf}
\graphicspath{{../Visuals/}{../Visuals/Chapter_1/}{../Visuals/Chapter_2/}{../Visuals/Chapter_3/}{../Visuals/Chapter_4/}{../Visuals/Chapter_5/}{../Visuals/Chapter_6/}}
\usepackage{gensymb}
\usepackage{times}
\usepackage{chemformula} % Formula subscripts using \ch{}
\usepackage{adjustbox}
\usepackage[british]{babel}
\usepackage{csquotes}
\usepackage[backend=bibtex, citestyle=ieee, bibstyle=ieee]{biblatex}
\addbibresource{Libraryv1.69,test}%multiple .bib files here for different chapters
%\addbibresource{test}
\usepackage[section]{placeins}%Allows you to permanently fix figures. 
\usepackage{titleps}%fancy page borders? 
\usepackage[left=4.0cm, right=4cm, top=3.5cm, bottom=3.5cm]{geometry}
\captionsetup{format=plain, font={small,it}, labelfont=bf}
\usepackage{microtype}
\usepackage{wallpaper}
\usepackage{setspace}
\usepackage{amsmath}
\usepackage{lipsum}
\setcounter{secnumdepth}{3}

\sloppy%Makes sure that none of the text exceeds text width. Useful if have long chemical words. 

\DeclareUnicodeCharacter{2212}{-}

\pagestyle{scrheadings} % <--- Affects the page header 
% and page number in the footer.
\clearscrheadfoot
\ohead{\leftmark}  % comment out to 

\cfoot[\pagemark]{\pagemark}

\renewcommand{\sectionmark}[1]{\markright{\spacedlowsmallcaps{#1}}}
% Remove section number from heading

\sloppy%Makes sure that none of the text exceeds text width. Useful if have long chemical words. 

\DeclareUnicodeCharacter{2212}{-}

\doublespacing 
\begin{document}

%CHAPTER_1
\chapter{Introduction}

\lipsum

\chapter{Project 1}

%\printbibliography
\end{document}

Answer 1

Do not use more than one package for page header and footer! Package classicthesis loads package scrlayer-scrpage. Therefore you have to remove package titleps.

Example (I have removed all the unrelated stuff):

\documentclass[12pt,a4paper,headinclude=true,footinclude]{report}
\usepackage[T1]{fontenc}
\usepackage[dottedtoc]{classicthesis}% loads package scrlayer-scrpage and sets page style scrheadings

\usepackage{mathptmx}% replaces obsolete package times
\usepackage[doublespacing]{setspace}
\usepackage[british]{babel}

%\usepackage{titleps}% <- remove this package!!

\usepackage[left=4.0cm, right=4cm, top=3.5cm, bottom=3.5cm]{geometry}
\usepackage{microtype}
\usepackage{lipsum}

%\pagestyle{scrheadings}% <- not needed
\clearpairofpagestyles% <- replaces outdated \cleardscrheadfoot
\ohead{\leftmark}
\cfoot*{\pagemark}% <- short version of \cfoot[\pagemark]{\pagemark}

\begin{document}
\chapter{Introduction}
\lipsum
\chapter{Project 1}
\lipsum
\end{document}

Answer 2

There is a mix of classes, packages and options.

Option 1

Use \documentclass[12pt,a4paper]{report} and titleps to setup the headers.

Option 2

Use

\documentclass[12pt,paper=a4,dottedtoc, headinclude, footinclude=true]{scrreprt}, the KOMA-Script report, and its own way to specify the page headers and footers (and remove titleps !)

Option 1

\documentclass[12pt,a4paper]{report}% or book for the standard book class
\usepackage[T1]{fontenc}
%\usepackage[utf8]{inputenc}
\usepackage[dottedtoc]{classicthesis}
%\usepackage{url}
\usepackage{color}
\usepackage{graphicx, epstopdf}
\graphicspath{{../Visuals/}{../Visuals/Chapter_1/}{../Visuals/Chapter_2/}{../Visuals/Chapter_3/}{../Visuals/Chapter_4/}{../Visuals/Chapter_5/}{../Visuals/Chapter_6/}}
\usepackage{gensymb}
%%%\usepackage{times} 
\usepackage{chemformula} % Formula subscripts using \ch{}
\usepackage{adjustbox}
\usepackage[british]{babel}
\usepackage{csquotes}
%\usepackage[backend=bibtex, citestyle=ieee, bibstyle=ieee]{biblatex}
%\addbibresource{Libraryv1.69,test}%multiple .bib files here for different chapters
%\addbibresource{test}
\usepackage[section]{placeins}%Allows you to permanently fix figures. 

%% ********************************************* added <<<<<<<<<<<<<<<<<
\usepackage{newcomputermodern} 
\usepackage{titleps}%fancy page borders? 
\newpagestyle{main}[\sffamily]{
    \sethead[\chaptertitle][][]% even pages if twoside
    {}{}{\chaptertitle} % odd pages
    \setfoot{}{\thepage}{}% 
} 
\pagestyle{main}

\renewpagestyle{plain}[\small\sffamily]{
    \setfoot{}{\thepage}{}}
%% *******************************************

\usepackage[left=4.0cm, right=4cm, top=3.5cm, bottom=3.5cm]{geometry}
\captionsetup{format=plain, font={small,it}, labelfont=bf}
\usepackage{microtype}
\usepackage{wallpaper}
\usepackage{setspace}
\usepackage{amsmath}
\usepackage{lipsum}
\setcounter{secnumdepth}{3}

\sloppy%Makes sure that none of the text exceeds text width. Useful if have long chemical words. 

%\DeclareUnicodeCharacter{2212}{-}

%   %\pagestyle{scrheadings} % <--- Affects the page header 
%   %% and page number in the footer.
%   %\clearscrheadfoot
%   %\ohead{\leftmark}  % comment out to 
%   %
%   %\cfoot[\pagemark]{\pagemark}
%   %
%   %\renewcommand{\sectionmark}[1]{\markright{\spacedlowsmallcaps{#1}}}
%   %% Remove section number from heading   

\sloppy%Makes sure that none of the text exceeds text width. Useful if have long chemical words. 

%\DeclareUnicodeCharacter{2212}{-}

\doublespacing 
\begin{document}
    
    %CHAPTER_1
    \chapter{Introduction}
    
    \lipsum
    
    \chapter{Project 1}
    
    %\printbibliography
\end{document}

Option 2

\documentclass[12pt,paper=a4,dottedtoc, headinclude, footinclude=true]{scrreprt}% KOMA-Script report

\usepackage[T1]{fontenc}

%\usepackage[utf8]{inputenc}
\usepackage[dottedtoc]{classicthesis}
%\usepackage{url}
\usepackage{color}
\usepackage{graphicx, epstopdf}
\graphicspath{{../Visuals/}{../Visuals/Chapter_1/}{../Visuals/Chapter_2/}{../Visuals/Chapter_3/}{../Visuals/Chapter_4/}{../Visuals/Chapter_5/}{../Visuals/Chapter_6/}}
\usepackage{gensymb}
\usepackage{newcomputermodern} % added <<<
%\usepackage{times}
\usepackage{chemformula} % Formula subscripts using \ch{}
\usepackage{adjustbox}
\usepackage[british]{babel}
\usepackage{csquotes}
%\usepackage[backend=bibtex, citestyle=ieee, bibstyle=ieee]{biblatex}
%\addbibresource{Libraryv1.69,test}%multiple .bib files here for different chapters
%%\addbibresource{test}
\usepackage[section]{placeins}%Allows you to permanently fix figures. 

%\usepackage{titleps}%fancy page borders?  REMOVE <<<<<<<<<<

\usepackage[left=4.0cm, right=4cm, top=3.5cm, bottom=3.5cm]{geometry}
\captionsetup{format=plain, font={small,it}, labelfont=bf}
\usepackage{microtype}
\usepackage{wallpaper}
\usepackage{setspace}
\usepackage{amsmath}
\usepackage{lipsum}
\setcounter{secnumdepth}{3}

\sloppy%Makes sure that none of the text exceeds text width. Useful if have long chemical words. 

%\DeclareUnicodeCharacter{2212}{-}

\pagestyle{scrheadings} % <--- Affects the page header  and page number in the footer.
\clearscrheadfoot
\ohead{\leftmark}  % comment out to     
\cfoot[\pagemark]{\pagemark}

\renewcommand{\sectionmark}[1]{\markright{\spacedlowsmallcaps{#1}}}
% Remove section number from heading

\sloppy%Makes sure that none of the text exceeds text width. Useful if have long chemical words. 

%\DeclareUnicodeCharacter{2212}{-}

\doublespacing 
\begin{document}
    
    %CHAPTER_1
    \chapter{Introduction}
    
    \lipsum
    
    \chapter{Project 1}
    
    %\printbibliography
\end{document}

Answer 3

Solved. Not sure if this is the correct approach but by adding a \newpage before each \chapter solves the problem.