there is an advance:

[night moat]

Then we know pretty confidently that it could be an issue with shadowmask mode

[brave echo]

No, i dont think so... while in baked indirect, i set the lights to mixed again and rebaked the whole thing and the problem returned, so, the good thing now is that we can assume that the problem is the mixed lights

[night moat]

By shadowmask mode I might mean "lighting modes" in general

Mixed lights are realtime for direct lighting and baked for indirect, so they share limitations of both realtime and baked lights