nDisplay on a 8 GPU machine

Hello,

We have a machine with 8 quadro GPUs. Each GPU is directly connected to a dedicated projector. We are trying to setup nDisplay configuration with 8 nodes on a single host with UE 4.27 but there is apparently no way to force a GPU per node. We also tried on a machine with 2 quadro connected to 2 displays and we had the same problem. Only the first GPU is doing the rendering. Has anybody managed to use a dedicated GPU per node ? Is it possible ? We can use Windows or Linux.