A BSP converted to a Static mesh shows a much darker texture material when built with Static/Baked lighting.
This was reported and tested in 4.24.1 (CL-10757647). This was reproduced in 4.23.1 (CL-9631420) and Main 4.25 (CL-11028482)
Results: Textures are darker if using baked lighting
Expected: Texture to remain similar to how it was before lighting was baked
There's no existing public thread on this issue, so head over to Questions & Answers just mention UE-86935 in the post.