Hi Sam
From Magento version 2.2.2 - Enable/Disable cache dropdown is only available when you are in developer mode.
Currently your mode is set to production so only Refresh Cache option will be there in drop down and thats why you are not able to see Enable/Disable dropdown of cache.
if you want that options back, change your mode to developer by running below commands.
php bin/magento deploy:mode:show //it will display the current mode
php bin/magento deploy:mode:set developer // it will set mode to developer
After that refresh your admin page again and check Enable/Disable drop down will be there.
Note : In updated version of magento 2.2.2 few options is only available when we are in developer mode.
if issue solved,Click Kudos & Accept as Solution