After opening EZ Drummer in Logic it works fine. However it seems that when I switch to my guitar track or any other track and start tinkering with it for a bit and return to the drums, they stop responding. When I click the drums nothing happens. I tried dragging EZ Drummer back to the main monitor to see if that was causing it but nothing changed. Theres an on / off button on the plugin that i clicked and the light goes on and off but it still hasn't fixed the issue. Any idea what I'm doing wrong here ?

Seems like the only fix is to delete the track and start all over with a new track.