Gas bars disappear despite showing ample gas range remaining

Hi all,

I have a 2013 Volt Premium with 48k miles. Yesterday, I was running in charge sustaining mode (i.e. depleted battery) and I noticed the gas bars in the gas gauge disappear despite having over 100 miles remaining of gas. It was showing 3 gas bars or 1/4 tank when this happened. I will try to post a picture below. Once I got home and parked, I cut the car off, waited 10 seconds and started it back up and the bars were still gone. I plugged up and let it charge overnight. When I left in the morning the bars were back so all was good. Anyone else see this before?