I suggest to update Drupal 8 one click install to the Latest and recommended version. As of the date of this idea post, the recommended version is 8.3.7
Due to a security fix, it is recommended to update

Alternatively, users can use Drush as it is included in the Cloudways Stack, as follows:

1. Put the site in Maintenance mode via Drush : $ drush sset system.maintenance_mode TRUE

2. Clear cache via Drush : $ drush cache-rebuild

3. Run the update via Drush : $ drush pm-update drupal

4. Take the site out of Maintenance mode via Drush : $ drush sset system.maintenance_mode FALSE

If you run into the error "Unable to load class \Drush\VersionControl\Backup" Move the folder outside of the drupal root and try updating again OR call cloudways tech support to assist with security update.