Some of the references in my bib file are not appearing when I compile the file. In-text citation are with a question mark

I am using TeXstudio to write my thesis and I am getting issues with my .bib file. All the reference are in the bib file that I compiled from Mendeley. The issue is that some in-text citations appear as a question mark and they also don’t appear in the bibliography even when I use nocite{*}. When I compile this in Overleaf I don’t get such error.

My .bib file looks like this:

@article{Legras2010,
abstract = {We measured high-contrast visual acuity (VA)},
author = {Legras, Richard and Benard, Yohann and Rouger, H{'{e}}l{`{e}}ne},
doi = {10.1016/j.visres.2010.04.001},
issn = {00426989},
journal = {Vision Research},
keywords = {Aberrations,Adaptive optics,Multifocal contact lenses,Numerical simulation},
number = {12},
pages = {1185--1193},
publisher = {Elsevier Ltd},
title = {{Through-focus visual performance measurements and predictions with multifocal contact lenses}},
volume = {50},
year = {2010}
}
@techreport{cha,
author = {Charman, W N},
title = {{OPTICS OF THE EYE}}
}

…

And this is my document class:

 documentclass[letterpaper,12pt,titlepage,oneside,final]{book}

Does anyone know how to overcome this issue?