When using vector arrow notation (\vec) combined with \lVert and \rVert, the norm won't cover the vector arrow if a capital letter issued for the vector, but instead cover extra "white space" below the letter.
Also \left\lVert # \right\rVert or \Big\lVert # \Big\rVert don't fix the problem, as they drastically increase vertical size covering much more white space above and below the vector. I would like to use this notation also in text, which is why vertical size matters a lot.
An optimal solution would be achieved if it was possible to simply shift the "||" upwards s.t. they cover the vector arrow and the least amount of white space below the letter, is that possible?
Example:
\documentclass{article}
\usepackage{amsmath}
\begin{document}
\[
\lVert \vec{A} \rVert = \left\lVert \vec{A} \right\rVert = \Big\lVert \vec{A} \Big\rVert
\]
\end{document}

\left/\right. You can pass the manual size as optional parameter. Anyway you want\big, not\Big. – campa Feb 26 '21 at 12:07\bigdoes the job, thanks! – Larzeb Feb 26 '21 at 12:19