Ok I found out the problem.
When ejecting, expo is supposed to generate a metro.config.js file that looks like that:
module.exports = {
transformer: {
assetPlugins: ['expo-asset/tools/hashAssetFiles']
}
};
I presume it makes sure the assets are bundled correctly.
However I already had a metro.config.js file prior to ejecting that I needed for a svg library so expo didn’t generate a new one.
In future version of expo it would be practical if the eject process could add the necessary configuration inside the metro.config.js if the file already exists.