Why composer install timeouts after 300 seconds?

composer config --global process-timeout 2000

try composer update/install -o -vvv and check wether the package is being loaded from composer's cache.

if yes try clearing composer's cache or try adding -cache-dir=/dev/null.

To force downloading an archive instead of cloning sources, use the --prefer-dist option in combination with --no-dev.

Otherwise you could try raising composer's process timeout value:

export COMPOSER_PROCESS_TIMEOUT=600   ( defaults to 300 )

The easiest method is add config option to composer.json file, Add process-timeout 0, That's all. It works anywhere.

{
  .....
  "scripts": {
    "start": "php -S 0.0.0.0:8080 -t public public/index.php"
  },
  "config": {
    "process-timeout":0
  }
}