New flat, new problems – what next?

Just moved into Aero View Heights last month, possession was in March. Honestly, things nobody told me about are popping up. Initial snag list mein kaafi items the, like kitchen sink mein drainage issue, bathroom fittings loose. Builder ne thoda delay kiya but fix kar diye. But ab walls pe hairline cracks dikh rahe hain already, just two months in! And ek balcony wall pe thoda seepage bhi lag raha hai. Is this normal for new constructions? Matlab, itni jaldi issues aana? What's your experience with initial build quality? Should I push builder hard now or wait for more issues to surface? Confused about next steps.