(1): The analog and digital parts were originally separated to avoid digital interference from entering the analog part. Your analog ground and digital power supply overlap, and a distributed capacitor will be formed in the middle, just like a decoupling capacitor. The interference of digital power supply will enter the analog ground through these distributed capacitors, which will seriously lead to the interference of the analog part. The correct way is that the digital power line and digital ground line overlap. Enhance coupling.
(2): Like the previous question, the interference in the digital ground also enters the analog ground through the distributed capacitor.