Roomster 2011 fuel gauge issue

Hi all,

I've got a 2011 Roomster with this style of digital fuel gauge.

In the last week since I last filled the tank, the petrol gauge will random show as the tank is completely empty.

Sometimes turning the engine off and on sorts it out. Sometimes nothing helps it.

I assume it would be linked to the fuel sensor in the tank?

Has anyone had this done before, is this an expensive thing to sort?

Thanks.