You need to exclude below scripts from minify to work Edd Social Login with Better WordPress Minify.
--> edd-slg-public-script
--> edd-slg-unlink-script
--> edd-slg-fbinit
If FES is activated, you will see enable Edd Social Login options on settings page like below screenshot:
Edd Social Login will only assign frontend vendor role to user if you have selected the default role from wordpress settings page like below screenshot:
If you have enabled the settings then you will see social login buttons on FES login and FES register page as below screenshot: