External Monitor Issue

I recently started using a Samsung HD4K monitor with my MBP 15 inch Retina display late 2013. Machine has 16GB of memory and an NVIDIA GeForce GT 750M 2048 MB video card.

I am thinking I might have some settings wrong on the VM.

The issue I am having is that when I resize the monitor larger after plugging it into the MBP, the external monitor screen goes black and I have to reboot the VM and then the monitor will work fine until I unhook it and plug it back in again. I have video memory set to 1GB and the CPU & Memory set to 2 CPUs and Memory set to 2GB.

Any thoughts?