How to get accurate Precomputed AO Mask?

Hi, i’m using the Precomputed Ao Mask node to cast a simple black layer on my material, but i failed to get a nice result. It seems that the resolution to which the ao mask is computed is far too low. I contrasted it in the image below so you can see what i mean. I tried to change the world lighmass settings, increasing the meshes distance field resolution, tried to blur the mask a bit and controll it with a 3PointLevel node. No good solutions, even online.

There’s anyone that have managed something better than this? Thanks!