Hey!
I have a few rooms, connected to each other. For lighting, I use "OmniLight3D". Randomly I have a strange behavior: looks like some of the lights don't work or have conflicts (I don't know)
That is the correct version:

That is broken:

And this is how my 3d scene looks:

I have Godot 4.1.3 (Steam version), "Mobile" renderer, but also I've tried "forward +", the same problem. I've also tried using VoxelGI with baking, in all cases I have the same random problem. If I move my room a bit or move lights while scene is playing, the lights will be fixed. Room - is a blender imported model by auto godot import, there is nothing else, only room + lights.

I really don't know what is wrong, hope someone can help me.
If you need more screenshots or details, let me know.

Forward+ and baking are the things I would have tried first too. Are any/all of the omnilights also emitting realtime shadows? I wonder if that could have something to do with it. If you'd be willing to share your project, that would probably help people better diagnose the issue. If you don't want to do that, then a video of the issue might also be helpful.

    Not related to your problem: I really like the look of your models and the colors!

      award
      Thank you for your answer and recommendation. I've recorded a video, here I've used a Forward +, all lights in static mode, all is baked.
      Here is a link to video on Drive: video
      As you can see, when 7 rooms were added, all rooms had a problem with lighting. Maybe I use wrong approach for lighting? (I'm aiming on mobile devices)

        Ah, this video helps a lot! (Very cool looking game you're developing, btw)

        I thought you had 8 omnilights total, not 8 per room. It seems very possible you're running against some kind of limit. https://docs.godotengine.org/en/stable/tutorials/3d/lights_and_shadows.html#light-number-limits

        You've probably read that already, but linking just in case. So you said you tried baking using VoxelGI, but that seems odd considering that the baked lightmaps should contain all of the light applied to the room. You should be able to bake the lightmaps, remove the omnilights, and still have all the light applied to the geometry. Then your only worry should be lighting dynamic objects.

        That's clearly not what's going on here though, so something is amiss. Did you follow the steps for static lightmapping & unwrapping on scene import? https://docs.godotengine.org/en/stable/tutorials/3d/global_illumination/using_lightmap_gi.html#unwrap-on-scene-import-recommended

        I'd try making sure at least one single room is correctly lit while having no lights active to see that the lightmap is behaving properly.

        There may be something else I'm missing. Sorry I don't have a ton of expertise in this area.

          award
          THank you for your detail answer. You are right, I used VoxelGI with Lights Nodes.
          I've replaced VoxelGI with LightmapGI, baked it, then turn off all lights nodes in rooms. Now as you said, my rooms have lighting without light nodes. And it's cool! Thanks!
          But I still have the same problem. Only first 8 rooms can be added without lighting problems, start with 9 there is problem with light. Also If move camera closely to room, Godot turn on lights in this room, but in viewport still present other rooms, and lighting for them will be turned off. Looks like Godot has some limits even without lighting nodes.
          I've tried to increase limit for light per scene from you 1st link.
          Here is an example, that I have room with lights without lighting nodes

          and as I said, only first 8 rooms are normal. But if I move camera closely (whole room will be in viewport) to dark room, light turn on

            Oh that's so weird. It's like if a texture stopped working when you had too many. I'm not seeing anywhere that there should be a limitation on lightmaps rendered at once. Ugh, sorry I can't be more help. Maybe someone in the #advanced channels on the official discord would be of some help to you. That place gets a lot more foot traffic than here. May as well give them a link to this thread here since you've laid out the issue and attempted solutions. This feels worthy of a bug report on github, but it might be difficult to reproduce without a minimum reproduction project.

              award
              Anyway, thank you so much for your help! I will try to ask on Discord