Griso Fuel light

Anybody had an issue with this, lights up on ignition/start, but doesn’t appear to on the road? fortunately at the top of Painswick Hill glos so not much of a push. went through the menu settings Mode thing as I wanted to increase the background light which was already on high, noticed that Average MPG was NOT recorded? possibly linked to fuel sensor malfunction?. Still under warranty but nice to know if anyone can shed light on what appears to be a gremlin. Regards Rat