No event handlers fire with React production build using Rollup - reactjs

Question

In our project we're using Rollup to build/bundle our code with code-splitting via React lazy on our routes. With a development build, everything works fine; our button and dropdown event handlers fire. In a production build, none of the handlers fire. It gets more interesting. If we don't do code-splitting at the route level and just have a single bundle file with everything, both development and production builds work perfectly. I'm wondering if I'm missing an option for any of my Rollup plugins that is causing this behavior?
envVars.exclude = 'node_modules/**';
envVars.preventAssignment = true;
const minifier = isDebugBuild ? null : terser();
rollup({
preserveEntrySignatures: false,
input: paths.scripts.src,
plugins: [
replace(envVars), // Replace all env vars.
nodeResolve({ // Resolve any imported node modules.
browser: true // Ensure all node modules are ready for browser use.
}),
json(), // Convert imported json files as modules.
commonjs({
include: 'node_modules/**'
}),
babel({ // Have Babel transpile our scripts to es6.
babelHelpers: 'runtime', // Include Babel runtime helpers in our scripts.
exclude: 'node_modules/**' // Don't transpile any modules imported from node.,
}),
minifier
]
})
.then((bundle) => {
const entryFileOutputName = isDebugBuild ? paths.scripts.entryFile : paths.scripts.entryFileMinifiedName;
const chunkFileOutputName = isDebugBuild ? paths.scripts.chunkFile : paths.scripts.chunkFileMinifiedName;
return bundle.write({
dir: paths.scripts.build, // The final output directory.
entryFileNames: entryFileOutputName, // The main entry script.
chunkFileNames: chunkFileOutputName, // The chunk scripts that will be lazy loaded.
format: 'es', // The final format of the bundles scripts. Here we want ES6+ JS.
sourcemap: isDebugBuild // Generate source maps or not.
});
});