Lighting only view mode and performance questions

Hello,

After building lights I used the lighting only view mode and I get this : Screenshot - f3dc8be41b556a08e85a82e4822560cc - Gyazo
Other room are like this : Screenshot - a14c08b764ee537005d2147d4c24e6f0 - Gyazo

In the first room (from the first screen) I got bad performance in VR. Everywhere I’ve 11ms latency for the frame and 22ms for the gpu BUT in the first room this gpu number goes up to 30/33ms when moving the head.
I used the gpu profiler and saw that light where causing an huge cost but not more than in other rooms.

Is the light causing the latency problem ? Meshs ?
Why my meshs disappear in lighting only view mode ?

Thanks