Hello,
So, Im working on a scene and for some reasons there are really weird glitches on the walls of the apartment. The UV is clean and I cranked up the lightmap settings to 2048. But it doesnt look likes the problem are shadows. I dont know what it is actually. Take a look at the picture and if any one have an idea that would be great. If you need any other information ask away. I need this fixed asap. 
Thanks for the help!
I augmented the r.streaming.pool.size to 8000, didnt fix it.
So far I have tried placing the mesh in other scenes. In every other scenes, the weird glitches are gone, but we are having lighting issues even though I did cut the walls in many meshes to increase the lightmap UV space and reduce errors. Its always and only the ■■■■walls that are bugged, nothing else. We are also using huge lightmap, like 2048 but when we look at a bought architectural project on unreal, his lightmaps even on walls were at a meager 64 and it looks great… what the hell?