Can not get redirect back to index.html on 404

I am trying to get redirections back to index.html when foo parameter is given after cloudshareimage/foo instead of a 404....with foo removed. Or any other parameter for that matter.

Any idea why this is not working on nginx?

server {
        listen   80; 
        server_name  www.cloudshareimage.com cloudshareimage.com;

        access_log  /var/log/nginx/cloudimageshare.log;

  client_header_buffer_size 128;

  expires -1;
  access_log /var/log/nginx/cloudimageshare.log;

  root /var/www/cloudshareimage/app/static/;
  error_page 404 = @notfound;

        location / {
           error_page 404 = @notfound;
        }

        location @notfound {
            return 301 /;
        }

}

 - - [27/Mar/2020:07:54:50 -0500] "GET /foo HTTP/1.1" 404 233 "-" "Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/76.0.3809.132 Safari/537.36"