(Repost) Warning only on certain citations, and I don't know why

Repost: I am new to the TeXSE and received comments on how I should be posting a full example, and so here it is. Thank you to anyone that pointed this out.

So I am using texmaker with Miktex, and only 2 out of 6 citations is undefined apparently, with the error message "Citation X on page Y undefined". I don’t know if this information helps, but I first wrote in the 4 that works into the bib file, then referenced it in my main document (i.e. addbibresouce and printbibliography). Then later I added the 2 more references to my bib file, saved it, ran pdflatex→bibtex→pdflatex*2, but there still is a warning. By the way, texmaker does autofill for all 6 entries, so I think texmaker recognizes the references, but the compiler doesn’t… Maybe it’s the way I wrote it though so the following is the bib file. The last 2 doesn’t work.

@Book{Abel1824, 
title = {Mémoire sur les équations algébraiques où on démontre l'impossibilité de la résolution de l'équation générale du cinquième dégré}, 
publisher = {Groendahl}, 
author = {Abel, Niels Henrik}, 
year = {1824}
}

@misc{Knill2004, 
url = {http://www.math.harvard.edu/archive/21b_fall_04/exhibits/2dmatrices/ index.html}, 
journal = {Eigenvalues and Eigenvectors of 2x2 matrices }, 
author = {Knill, Oliver}, 
year = {2004}
}

@misc{Sanderson2019, 
url = {https://www.youtube.com/playlist?list=PLZHQObOWTQDPD3MizzM2xVFitgF8hE_ab}, 
publisher = {YouTube},
author = {Sanderson, Grant}, 
year = {2019}, 
month = {3}
}

@Book{Taylor1715, 
place = {Londini}, 
title = {Methodus incrementorum: directa & inversa}, 
publisher = {Apud Gul. Innys}, 
author = {Taylor, Brook}, 
year = {1715}
}

@Book{Arfken1999,
title = {Mathematical methods for physicists},
publisher = {American Association of Physics Teachers},
author = {Arfken, George B and Weber, Hans J},
pages = {217--229},
year = {1999}
}

@Book{Strang1993,
title = {Introduction to linear algebra},
author = {Strang, Gilbert},
volume = {3},
year = {1993},
publisher = {Wellesley-Cambridge Press Wellesley, MA}
}

Main document:

documentclass[12pt, a4paper, onecolumn, leqno, oneside, titlepage]{article}

usepackage[backend=bibtex, style=numeric, sorting=nyt]{biblatex}
usepackage[nottoc,numbib]{tocbibind}

addbibresource{bib}

begin{document}

cite{Taylor1715}
cite{Knill2004}
cite{Abel1824}
cite{Sanderson2019}
cite{Arfken1999}
cite{Strang1993}

section{References}{
nocite{*}
printbibliography[heading=none]
}

end{document}

I would really appreciate it if y’all can help me. The "only 2 I added later doesn’t work" thing really bugs me out.