Citation sections are bold, biblatex

Question

I am using a custom biblatex template for my references. For some reason, the conjunction "and" is always bold. I want to make all my author name related citation sections plain.

Here are screenshots:

Reference list:

Intext citation: My code looks the following way:

\documentclass[10pt,a4paper]{report}
\usepackage[T1]{fontenc}
\usepackage{amsmath}

\usepackage{subcaption}
\usepackage{caption}
\captionsetup{skip=0pt, textfont=it, justification=centering, width=0.8\linewidth} %caption parameters

\usepackage{gensymb}
\usepackage{siunitx}
\sisetup{
    round-mode          = places, % Rounds numbers
    round-precision     = 2, % to 2 places
}
\usepackage{multirow}
\usepackage{booktabs}
\usepackage{fullpage}
\usepackage{multirow}
\usepackage{babel}
\usepackage{csquotes}
\usepackage{amsmath}
\usepackage{amssymb}
\usepackage{graphicx}
\usepackage{enumitem}

\usepackage[
backend=biber,
style=ext-authoryear-comp, giveninits, uniquename=init, maxbibnames=999,
urldate=long,
innamebeforetitle, articlein=false,
]{biblatex}
\DeclareDelimFormat*{nameyeardelim}{\addcomma\space}
\DeclareDelimFormat[textcite]{nameyeardelim}{\addspace}
\DeclareDelimFormat{andothersdelim}{\addcomma\space}
\renewcommand*{\compcitedelim}{\multicitedelim}
\makeatletter
\AtEveryCitekey{\global\undef\cbx@lastyear}
\makeatother
\DeclareNameAlias{sortname}{family-given}
\DeclareFieldFormat{biblabeldate}{#1}
\DeclareFieldAlias{biblistlabeldate}{biblabeldate}
\DeclareDelimFormat{editortypedelim}{\addspace}
\DeclareDelimFormat{translatortypedelim}{\addspace}
\DeclareFieldFormat
[article,inbook,incollection,inproceedings,patent,thesis,unpublished]
{title}{#1\isdot}
\newcommand*{\mkbiburlangle}[1]{<#1>}
\DeclareFieldFormat{url}{Available at\addcolon\space\url{#1}}
\DeclareFieldFormat{urldate}{\mkbibbrackets{Visited:\space#1}}
\renewcommand*{\jourvoldelim}{\addcomma\space}
\renewcommand*{\volnumdelim}{}
\DeclareFieldFormat[article,periodical]{number}{\mkbibparens{#1}}
\renewcommand*{\volnumdatedelim}{\addcomma\space}
\DeclareFieldFormat{issuedate}{#1}
\DeclareFieldFormat{doi}{\url{https://doi.org/#1}}

\addbibresource{businessreport.bib}
\renewcommand*{\nameyeardelim}{\addcomma\space}

\begin{document}

Sentence with citation \parencite{Mullins2016}.    

\printbibliography

\end{document}

And my bib file would look like:

@book{Mullins2016,
address = {Harlow},
author = {Mullins, Laurie J. and Christy, Gill},
edition = {11th},
isbn = {978-1-292-08848-8},
publisher = {Pearson Education Limited},
title = {{Management and Organisational Behaviour}},
year = {2016}
} 

Answer 1

You are loading babel but setting no language, so biblatex gets disrupted for not knowing the language of the document, and what you see are the bibstrings names, not their values (thus they are typeset bold). If you need babel for English, set the language with \usepackage[english]{babel}.

\documentclass[10pt,a4paper]{report}
\usepackage[T1]{fontenc}
\usepackage[english]{babel}

\usepackage[
backend=biber,
style=ext-authoryear-comp, giveninits, uniquename=init, maxbibnames=999,
urldate=long,
innamebeforetitle, articlein=false,
]{biblatex}

\addbibresource{businessreport.bib}

\begin{document}

Sentence with citation \parencite{Mullins2016}.

\printbibliography

\end{document}