we are also working on a horror project and we have movable doors and drawers which are totally black after build.
if you move and rotate each level from inside it ( select all assets then move or rotATE some where you want it to be in its persistent level which in our case is the world map where all levels are there as sublevels) instead of moving levels using level details panel. and then create a “build map” per level and add a level to it and build then when you open the world map those sublevels with their build data will be there correctly . for example a build map named hospital_build then add hospital to it and build lights then add hospital to the world. it can solve some of your current issues then you can remove movable lights and get a better result. our current problem now is more complex than yours i think.
when using light visualizer it only shows us light data of only one level I mean if have two levels loaded then light visualizer shows only one of them and in runtime when a we want to load another map its indirect light appears in the current level and makes all movables dark.