Can I activate the Clover Connect Payment Processor plugin again?

Can I activate the Clover Connect Payment Processor plugin again?

Yes, you can always choose to reactivate the Clover Connect Payment Processor plugin. However, there are 2 possible scenarios here.
Scenario 1: 
Your reactivation date is BEFORE the end of your current billing cycle. In this case, you just need to click the activate button on the Clover Connect Payment Processor plugin tile (if you are coming from the Plugin screen) OR put a tick on the activation checkbox on the Clover Connect Payment Processor plugin tile (if you are coming from the Manage Account section) to activate it.
Scenario 2: 
Your reactivation date is AFTER the end of your current billing cycle. In this case you will have to again subscribe to the plugin through the normal subscription process. 
Plugins in Tagrain are either Subscription Based or License Based. So the price that you pay for your plugins is based on the number of POS terminals that you have in your setup and the number of licences that you have acquired.
There will be no change in your subscription amount in the current billing cycle if you are only deactivating the Clover Connect Payment Processor plugin AND not updating your Store / POS count. 
Activating or Deactivating the Clover Connect Payment Processor plugin will not affect your subscription amount for your next billing cycle because the plugin is free.