Enterprise browser - apps in tabs not responsive


I am using a TC21 device on Android.
I've configured the EB via the config.xml and the tabbar.xml to open 2 web applications in different tabs.
However, the apps in these tabs are not responsive, and are showing a desktop site.

I've tried setting the viewport width in the config.xml , to no avail.
There should be a settings button in the EB itself, if there is no home page set, but I couldn't manage to get it to show.

How can I configure the EB correctly?