Giovanni di Bari

I have an issue related to this https://github.com/JP-Ellis/tikz-feynman/issues/32. I have this LaTex code ``` \begin{align} \labeq{lqed} \mathcal{L}_{Q E D}&=-\frac{1}{4} F_{\mu \nu} F^{\mu \nu}-\bar{\psi}\left(\gamma^{\mu} \partial_{\mu}+m\right) \psi+i e A_{\mu} \bar{\psi} \gamma^{\mu} \psi...

I'm getting the error `Underfull \hbox (badness 10000)` at any chapter name. Not only those with a long chapter name, such as `\chapter{Quantization in Curved Spacetime}`, which gets split into...