As you are unable to get the automatic update I would recommend the manual method for updating theme i.e. using FTP agent like Filezilla to upload the file to the hosting
Assuming you have your existing theme folder backed up – and that you do not have theme customizations stored in the main theme folder – it’s now simply a question of dragging your new Avada theme folder, which you can download from themeforest, into wp-content/themes via FTP to override the existing content.
Please read more about this at https://theme-fusion.com/avada-doc/install-update/how-to-update-theme/ under heading “How To Update Your Theme Via FTP” http://puu.sh/kHk9o/a46061fac7.png
Always check our important update information before you update:
How to update your theme to the latest version of Avada:
Make sure you also update our included plugins:
Other important reminders:
1. Please make sure you backup your entire site first – either via cPanel, or manually back up your WordPress, Avada, uploads folders as well as your WordPress database. Your web host support can guide you more about backup options on your hosting account.
2. Do not leave older copies of Avada in WP themes folder when updating to a newer version of Avada. Old copies should be removed completely before uploading the new version to prevent errors with Theme Options, loss of menus and widgets, and other issues. THIS IS VERY IMPORTANT.
3. Clear browser and any plugin caching systems after updating the theme. Cache can display false views of the theme pages after updating. This is also true when updating plugins as well.