LaTeX Latex Disappeared: Why Is Text Flux $\pi$ Text Intensity?

[yucheng]

This is my thread, here at https://www.physicsforums.com/threads/why-is-text-flux-pi-text-intensity.1007599/

I initially pasted the latex formulas in, but then after previewing and then reverting back to editing mode, the latex disappeared and is replaced with unicode. What's wrong? (actually, in between, I used the more options button to use the full editor)

By the way, I am also facing the same problems as

https://www.physicsforums.com/threads/unable-to-preview-latex.1007118/

 

[Frabjous]

The thread shows up as expected for me (Safari on ipad)

 

[yucheng]

The thread shows up as expected for me (Safari on ipad)

yeah I edited it. The picture refers to the original post where the latex disappeared.