Again the action vs. attack die terminology confusion strikes. At fifth level the attack die is a d7. You roll it and add it to your action die total on each attack. As written, if you roll a d20+d7 and get 12+7 you have a 19 (plus other modifiers) for your first result. You then keep the 7 on the attack die and will need to roll a d14 for your other action. Knowing that you have a +7+other modifiers before rolling the d14 seems wrong to me for a couple reasons.
That is why I think the rule either needs to be that all action attempts for the turn are declared before any dice are rolled, or you should reroll the attack die for each attack. The first has the problem that sometimes a character will do a nonsensical action, like casting a spell at a dead adversary because the first half of their action worked as an elf. Of course, you could interpret this as the fun in the game. Still, I'm advocating for the latter approach and just re-rolling attack die with each attack.
yup, that's what's happening here. I've already gotten use to the difference between an Attack Die (only Warriors and Dwarfs have them) and Action die (the d20 you roll to attack, among OTHER THINGS.) Class Die is would totally eliminate the confusion.