You may have a console error due to some other plugin in your admin area. You can deactivate your plugin one by one to see if this error is fixed. Also, try to check the plugin in different WordPress installation (if the same problem occurs). For further support, please open a support thread.
Thanks for sharing your review. I have checked timeline editing by clicking on pen symbol and it is working correctly. This problem may occur due to some other reason. Make sure you have the latest version.