Have you tried Nvidia's built-in tool that is available? nvidia-smi?? It shows what is running on each gpu, the amount of utilization, memory usage, power usage in watts and each application running on each particular gpu.

You can find it in C:\Program Files\NVIDIA Corporation\NVSMI

Just open a command window and type nvidia-smi.

Have you tried???

<use_all_gpus>0</use_all_gpus>

A 1060 (6.1) is more capable than a 940MX (5.0).

<use_all_gpus>0|1</use_all_gpus>
If 1, use all GPUs (otherwise only the most capable ones are used). Requires a client restart.

https://developer.nvidia.com/cuda-gpus