The Sony a6400 still boasts the 24.2 MP APS-C sensor but has overall better light sensitivity with the native ISO range going from 100 - 32000 and more.
Sony A6400 review
Sony A6400 review: Finally, a Sony camera I actually want to buy - SoyaCincau
Academic Tech] Sony a6400 'review' – Prof. Peter L. Falkingham
Sony Alpha a6400 Mirrorless Camera Review: Is It Worth The Hype? [2023]
Sony A6400 Review and How-To Use The Camera
Sony A6400 Review
Sony A6400 Mirrorless Camera Reviews – Affordable, Amazing AF, and Great for Vlogging!! – SonyAlphaLab
Sony a6400: Sony α6400 (ILCE-6400) review: Ultra-fast autofocus coupled with AF tracking makes it a good buy - The Economic Times
Sony a6400 review: A quality mirrorless camera with amazing autofocus