Is Https: automatically switched On?

In SSL/TLS settings I have the mode as Flexible

Is https automatically switched on, if not how do I change it?

To be honest: you are not secure with flexible.

If you set the settings ‘Flexible’, TLS will be activated immediately. Use ‘Always use SSL’ and 'Automatic HTTPS Rewrites" to redirect visitors automatically.

If you’re running Wordpress and encounter too many redirects after that, use the forums search to solve it.