Fixed it.
If the menu tabs(#basic, delivery, advanced) are not showing in settings-> general you need to stop inline of css fonts.
I specifically had an issue with the Wp- optimize plugin minify -> fonts -> inherit from css settings.
To fix this tabs menu not being displayed simply change the font option under google fonts to ” Asynchronously load CSS files from Google Fonts”
Save and then go to newsletter plugin and you should see your tabs!
Hope it helps someone!