[Tex/LaTex] Bold and italic command is not working

formattingluatexxetex

I've tried \bfseries and \textbf{} for the bold and \textit{} or \emph, but neither change the text. I'm really not sure what can I do. I'll put some examples of the code I have.

\titleformat*{\section}{\normalsize \bfseries}
\titleformat*{\subsection}{\normalsize \bfseries}

this one will put in normal size the title but not in bold.

{\noindent\bfseries{Key words:}\textit{ abc, abs, abc}}\\ 

{\noindent\bfseries{Abstract: }\textit{\blindtext }}

Again, the other commands works but not italic or the bold.

As far as I know, I'm using all packages necessary. Thank you for the help!

EDIT:

\documentclass[a4paper,12pt]{article}
\usepackage[english]{babel}
\usepackage{fontspec}
\setmainfont{Times New Roman}
\usepackage[T1]{fontenc}
\usepackage{titlesec}
\usepackage{titling}

Best Answer

Never do

\setmainfont{Times New Roman}
\usepackage[T1]{fontenc}

Do not use fontenc with luatex or xetex, with those engines you want to use Unicode (TU encoding) not the 256-character tex-specific T1 encoding. TU is already set up by default (in current formats or by fontspec package even in older formats) so you do not need to specify the encoding.