GCP Load Balancer - Host and path rules not working
Looking by the error 404, I guess the server is reached, but the paths like /website-1/bundle.js may not be mapped to appropriate resources. But your server seems to be responding to /bundle.js kind of paths since they may be mapped. So basically try to map these paths on your web server so that your website can be served from /website-1/ or /website-2/ paths as well.