URP Lightmap breaks on edges

I have a simple building setup with windows (emissive glass material vs bloom post-processing). My idea is to add point lights to highlight the wall around enlighted windows.

Realtime lighting looks great.


But, of course, you can't have real time light for each and every window. So, I'm trying to bake it.


Result is the following. Light is just goes "all squares", spliting by shape edges (building is one very large object converted into mesh, while each window block was initially a seperate objects).

Same time, environment light is baking great (you could see very accurate diagonal shadow somewhere on the left wall).

I see there are ton of conversations on baking but usually the questions have different nature. It feels my questions are stupid and could be related to lightmap UV unwrap (I'm using Unity unwrap on import) or some baking settings.

Posting this with hope some of the pros will recognise the problem just from the way it looks.

Thanks a lot!

 

This is how lightmap looks. Obviously, something is wrong. But what exactly? Sorry, I'm super new to this.

 

Always use other software's for UV Unwarp for accurate models (like interior models). for example Maya LT Unwarped uvs are much better for lightmapping
I have already proved this a few years ago
Maybe this video be useful for you: