When traffic is up but conversion is flat, the loud answer is to redesign. The quieter, harder answer is to look at what visitors were promised before they got there. If the ad said one thing and the landing page says something else, no amount of new typography fixes that.
Audit the path: ad copy → landing headline → first paragraph → primary CTA. Each step should answer the question raised by the one before it. Most funnels we look at have a break in that chain — and once you mend it, the design starts working.