Hi, I wonder if anyone can help please?

I have a Sony Xperia SP and a few days ago was told that it needed to update, so I let it do this but now I've found that the light feature, which used to light up along the bottom of the phone when it rings or someone sends a text, no longer does! Going to my Settings, it's still showing as being chosen but nothing happens. I've tried restarting the phone but no joy. It's really annoying, that was a helpful feature, especially when it lit up if I hadn't heard a text come through.

Can anyone offer any help please?

Many thanks in advance,