Odd "syntax errors" when launching an image on macOS, but not on Linux

I have the following Dockerfile:

FROM node:18-slim

COPY . /opt/app

WORKDIR /opt/app

RUN npm i

EXPOSE 8080/tcp

CMD /bin/bash npm run dev -- -- --api-listen-addr 0.0.0.0:8080

(For full context: create-chiselstrike-app: Generate Dockerfile by penberg · Pull Request #1787 · chiselstrike/chiselstrike · GitHub)

When I fly launch from a Linux machine with podman installed, it deploys fine and I can access my application.

However, when I do the exact same thing from macOS, I see errors like this when attempting to start the application:

2022-09-22T08:34:37.000 [info] /opt/app/node_modules/binary-install/bin/chisel: 1: Syntax error: "(" unexpected

That file is supposed to be a Linux binary and the Docker image is also tested to be OK.

How is the fly launch process different on Linux and macOS?