If I understand correctly, in your scene light enters the room through the open door. If the door is closed, the room is dark, if open, is illuminated. In this case you cannot use GI cache. GI cache is used, if you have a static environment and static light. A cache is applied to dynamic objects that are moving in the scene. Try LPV - Light Propagation Volume. It is fully dynamic system of calculating the GI in real time.
thks! but light propagation V cost too much! i want to deploy my project on mobile devices too ! things i don t understand everything is static in my scene and i use stationary light for all even static light ! there is only just those door that are movable !
(just in case you don t have information about how to set up gi cache ! )
thx to you