Here are two screenshots taken from 3D rotation matrix with zero determinant and Simplify this expression for the relative condition number of $f(x,y) := [ x^y, x + y ]^T$. It can be seen that an extra space is added between the left bracket and the matrix body. I have also tested some other matrix-like environments such as
vmatrix, and there is always such a space added next to the left delimiter.
Is this due to some updates of MathJax or my browser? I am using Internet Explorer 11. Thanks.
Edit: This anomaly occurs when the renderer is HTML-CSS but disappears when the renderer is common HTML, preview HTML or SVG. The versions of related scripts are:
TeX Input Jax v2.7.5 HTML-CSS Output Jax v2.7.5 PreviewHTML Output Jax v2.7.5 mml Element Jax v2.7.5