In order to copy over events from one session to another, you MUST set the current Session you are copying to so that it is the Default Session. Please read the below article on how to do so:
How to Change Default Registration Session
Step 1
Login to your Administrator account and go to the Registration & Membership area.
Step 2
Click Copy Events on the top right of the page.
Step 3
Select the Session you wish to copy from.
Step 4
Select the events you wish to copy over using the checkboxes on the left. Click Copy Selected Events. Your selected events will be copied over to your current (Default) Session. Be sure to edit the dates and information of your copied over events before opening it up to the public.
