2 GPUs (GTX 1070, GTX 970) setup issue or bug when maximizing window.

I have ubuntu Linux 16.04 with the 370.28 driver. I have the same issue with archlinux.

The GTX 1070 is connected to 4 4k monitors and the 970 connected to 1080p and a 4k monitor.
On some applications when I maximize the application it spans on more than one monitor, which is not desired. This is resolved when I set “BaseMosaic” “on”, but then I loose access to the monitors connected to the second GPU.

Is there a way to span an application on one monitor only when using DUAL GPU.If possible also to move application from a monitor connected to one GPU to a monitor connected to the second GPU (without using Xinerama.

Thanks for any help.