Hello there @Chantanclan !
Checking with my peers, stationary spots and rect lights are compatible on paper, but they do have different results when mixed with regular shadowmaps.
Searching around the community for this relation, I found a related bug report from last year, and an associated thread:
UE-291212 - GPU Lightmass no longer works with cascaded shadow maps
Since Unreal Engine 5.5 stationary lights have stopped working with GPU Lightmass when using Cascaded Shadow Maps.
With Virtual Shadow Maps enabled on the project, GPU Lightmass works. This issue does not happen with CPU Lightmass or in 5.4.
From this data, I think you can have two paths to try here:
- You can use virtual shadow maps instead of classics, which should avoid strange behaviours with shadows and objects
- Or you can switch your lights to static, which should bypass the shadowmap channel conflict, baking into the lightmap textures