The UVs were fine, but the lightmap resolution was a bit low (it appeared in a light blue in the editor), so that might be the issue here.
Also, I forgot that I had all the lights in Static, and after changing them to Stationary, everything went right. I think I’m gonna use a combination of static lights and stationary lights, for a better performance*. But I’ll check the lightmap res of my assets, so thanks for the advice!
*(PS: I’ve noticed that the Static lights doesn’t count for the light overlap when the lightmaps are generated. It should work right, doesn’t it?)