ConvertPlug and Rocket Cache are two premium WordPress plugins that we use on our client sites but recently we noticed when both of them are activated with full settings the ConvertPlug does not work. We struggled with this for awhile and could not figure out why the ConvertPlug Plugin would not work. Basically we could activate it, get it running but then it would stop displaying the pop-up.
We were able to fix this by testing different settings with Rocket Cache and then checking to see if the ConvertPlug worked. Eventually we found that if you are caching your Google Fonts that the ConvertPlug will not work. To fix it simply make sure you do not have the “Google Fonts” Caching Checked. Clear your cache and then ConvertPlug should start working.