Interior ArchViz light bleed problem

I’m doing a interior ArchViz project and encounter this problem. Because of the lack of UDIM support. I separate the wall and the ceiling to two meshes to gain higher resolution lightmaps. But the artifacts start to appear at the seams between walls and ceiling. Any clue to solve this problem?;base64


Try to avoid too large meshes. (impossible to set a high enough lightmap resolution)
Try to avoid overlapping faces. (or try to exclude them from your lightmap uvs)

Are the skylight or directional stationary? or are they static?

I separate them to smaller rooms. Join the ceiling and floor to the wall, make them to one seamless static mesh. Get a much better result. Thanks.

Yes, all the lights were set to static.