Probation being extended

[Lawrencepa2014]

I had my 3 month review recently and was told my probation was being extended. Even though it hadn’t been 6 months yet? It was a positive review apart from this and they said I’ve improved lots and they’re not so worried about my speed now. I haven’t had a complaint in 2 months. But their only problem was the fact that I haven’t taken much control when being out on delivery. And I need to be more “assertive”. Thing is I haven’t had to do that much van driving yet, I’m often the walker. There’s only one route I know very well but I’ve never been the driver on it. I don’t understand how I can lead the way when I’m not driver. So how can I improve this? And also do I have anything to worry about?