Server audit confirms proper allow_url_fopen parameter and same key and pair in my una.io account is also showing in site settings page. I will provide studio access details in messenger as suggested as after creating a new key pair and clearing cache it still does not show the upgrade button. Also, auto update tick box seems to disable itself after a few hours for some reason even though I re-check it and save.  Perhaps one of the bx files is overwriting that during an update check? 

Thank you that did the trick! Great find.