Unfortunately there's no way to check if the game is actually rolling 1 or 2 d20s without recording dozens of rolls w/Advantage and doing statistics on the results. I would like it if the game showed you both rolls when you rolled with advantage/disadvantage, as this would be easier to understand by players.
Wholeheartedly agree on this. There’s something really satisfying about rolling two dice, it would be great if they showed this onscreen. Kinda surprised they haven’t implemented this already – it would also help newbies get up to speed with the mechanic so much faster.