I am owning CB400 date 2009. I fueled my bike full tank few weeks ago. After running 120 km, now my fuel indicator still indicates full bar of fuel. It has happened since I dropped my bike on the left side at 40km/h

I guess the sensor and cable works well since the fuel bar still indicates full on my bike. But maybe the gauge inside fuel tank has problem?
Do you have any idea whats happening?