If you are having trouble with your green screen's not all dropping out the auto feature may not be "seeing" enough of the background to accurately analyze what to drop out. You can turn off the auto and lock it to green or blue to improve the drop out. Go to the Photos Tab of your event and double click on any image. That will open the editor and on the left you will see a column of tools (see below). If you do not see the tools show click on "more tools" at the bottom. Put a check in the green box as shown to lock in green then click on "attributes" at the top of the screen (see below). In the attributes drop down select "Save to" and then System Defaults". This will apply this setting to all future images for this event. You can also use the other adjustments on that same tool bar to correct for some lighting issues and other attributes.