Diagnose Signup Funnel Quality vs Friction

Scenario

You are a senior product analyst on a mobile-first consumer fintech app. Over the last 6 weeks, the overall funnel from app install to first qualifying direct deposit fell from 9.8% to 7.1%, while top-of-funnel installs increased 28% after new paid acquisition campaigns launched and the onboarding flow was redesigned to add an extra identity-verification step. Click-to-signup-start remained roughly flat at 41% to 40%, but signup-start to approved-account dropped from 62% to 51%, and approved-account to first qualifying direct deposit slipped from 38% to 35%. Leadership wants to know whether the bigger problem is lower-intent traffic entering the funnel or added product friction in onboarding.

Question

How would you analyze this funnel to determine whether the primary issue is acquisition quality or product friction, and how would you decide which lever to prioritize first?