some code ligatures fail in Node mode

[mbertucci47]

StackExchange question: https://tex.stackexchange.com/q/685434/208544

Some code ligatures from the JetBrains Mono font (available here) do not work in Node mode. For example

\documentclass[12pt]{article}
\usepackage{fontspec}
\setmonofont{JetBrains Mono}
\begin{document}
Some that work:
\texttt{<=>, <=|, </, and -->}

Some that don't:
\texttt{<->, ->>, >->, and <-<}

This is fine:
\texttt{<=>, <<-}

But this is not:
\texttt{<=>, <<-,}
\end{document}

Node mode

Harfbuzz mode

Some ligatures seem to never work and some only contextually work; see the last line with the comma added.

Adding [Renderer=HarfBuzz] fixes everything. I don't know if this is a bug but it was suggested by @u-fischer in the SE comments to report it.

Addendum: The issue is also there with Fira Code, with the same ligatures failing. Also fixed by using Harbuzz.