It's been noted quite frequently (and in the rental agreement, posted in locations and on Avis's site, and often on the rental contract printed by the location for you) that you must fill the gas AND present a receipt if driving <75 miles.
https://www.avis.com/car-rental/cont...g-US_en-029998
http://redirect.avis.com/services/fso/
Sure, they should ask for the receipt, but they don't.
I've used Chrome for a few years without issues on Avis' site. Are you using the .com or another Avis site?