Hi,
I can see that you're using the PDF invoice plugin. It could be coming from the fact you're using an old version of that plugin which doesn't support additional fees.
I checked your orders but I couldn't find any for the PDF invoice plugin so I don't know when you downloaded it and thus I'm not sure if the version you have supports additional fees.
I would recommend downloading the plugin's latest version on our website and installing it again.
If that doesn't help, we would need a backend and FTP access in order to check the situation more in depth.