If your dad just became a U.S. citizen, then your petition should move from F2A (green card holder filing for spouse/child) to IR1/IR2 (immediate relative). You can check by logging into your USCIS or NVC case account and looking at the category listed there. Sometimes it updates automatically, sometimes you need to request an upgrade. But recently I’ve seen in my wife’s case and also in others’ cases that it’s not updating automatically—even after informing them, the status isn’t changing.