For the front-end code, I am not sure how the footer is created. If it is created using WordPress Dashboard > Appearance > Widgets. Then please follow the steps below for translation:
It seems that you used a correct method to translate the footer in question.
It might be a compatibility issue between WPML and PenNews theme.
I can take a look at the issue. I'd appreciate it if you could give me the URL/User/Pass of your WordPress dashboard after you make sure that you have a backup of your website.
It is absolutely important that you give us a guarantee that you have a backup so if something happens you will have a point of restore.
Thank you for the login information. There seems to be a compatibility issue with the Footer Text option inside Appearance > Customize with the PenNews theme.
I suggest that you ask the theme developers on how to change the footer from those customize options to widgets from Appearance > Widgets.
That way you can create the footer of the website using widgets and translate them following the steps below: