Browser extension pdf text diff doesn't render math legibly

Maybe a font issue?
The code that produced ie the third line of the diff was
```
\frac{
2 (-1)^{\vec{n}}
}
{
1 - \left(
\frac{\vec{\lambda}_n^T}{ \vec{\lambda}_m}
\right)^2
}
```
so the empty box is perhaps the frac command.

Potentially just showing the diff of text mode and ie "four diffs in mathmode" would be more legible if actually rendering the math is too difficult.

No file or test is named. Start by locating the browser extension entry point that renders PDF text diffs, then reproduce the issue with the supplied LaTeX expression. Done means the math diff renders legibly, or a clearly legible text-mode fallback is provided.

Written by the indexing model from the issue text.