Latex error about disappeared "|| ||" notation

Steps to reproduce

when I inserted the latex equation $$ \left| f^{\prime\prime}(x)-f^{\prime\prime}(y) \right| \le M\left| x-y \right|$$, the norm notation “|| ||” about {\prime} disappeared. However, the notation “|| ||” about “x-y” was not disappeared.

Expected result

The latex code was compiled in TeXstudio. The image shown below was the expected result.

Actual result

The error result shown below was shown in Obsidian

the notation “|| ||” was disappeared!!!


  • Operating system: windows 11; Obsidian: v1.0.3