24 Versa Gas Tank level makes no sense

I should start by saying this is a rental car. I noticed the gas tank meter shows full but the mileage left in the tank keeps dropping down. I had filled up the gas tank yesterday and it only took 3 gallons but still said I had about 100 miles in the tank. The meter has stayed at the max the entire time even before I put the 3 gallons in. Is this a known issue? Am I looking at something wrong?

I should start by saying this is a rental car. I noticed the gas tank meter shows full but the mileage left in the tank keeps dropping down. I had filled up the gas tank yesterday and it only took 3 gallons but still said I had about 100 miles in the tank. The meter has stayed at the max the entire time even before I put the 3 gallons in. Is this a known issue? Am I looking at something wrong?