MathJax does not show the equations properly

Question

I tried to answer a question and in the edit mode MathJax shows the equations properly, but when I click on "save" some equations are not rendered (?) at all, and I see only the MathJax code.

If I click on edit again, everything seems to be OK, but in normal viewing mode it is screwed up on my Brave or Edge browsers. I tried to edit again, start a new answer, etc., but I still had the same problem. What is wrong with my equations?

Answer 1

This seems to be caused by the use of \label{}. Here is your first equation, with and without that command:

$$ h(t)\nabla \times \tilde {\mathbf H} = \mathbf J +\epsilon_0 \dot {e}(t) \tilde {\mathbf E} \tag{1}\label{1}$$

$$ h(t)\nabla \times \tilde {\mathbf H} = \mathbf J +\epsilon_0 \dot {e}(t) \tilde {\mathbf E} \tag{1}$$

Both look identical during editing, but the first is sometimes (but inconsistently) mangled in the output.

I'm unaware of how \label{} works in MathJax, and whether it is truly supported. But do you really need it? Why not use just \tag{}s, and hard-code any references in the text? (i.e. use $(1)$ instead of $\eqref{1}$.)