Thanks for joining the Graphics community.
Scaling options issues have been under investigation through our engineering department.
Please check the following thread for some assistance:
Please checkout newest driver posted for Haswell/Broadwell product generations (Intel HD Graphics 4200/4400/4600/5000 + Iris 5100 and Iris Pro 5200 + Intel HD Graphics 5300, 5500, 6000, Iris 6100, Iris Pro 6200):
You can set your preferred scaling option for desktop modes here - now the scaling preference is independent of current resolution and is "sticky" (retained when resolution change occurs). In addition, you can try checking the box selecting "Override Application Scaling" checkbox to force scaling of games to match your preferred scaling option (e.g. either full screen or maintain aspect ratio depending on your preference)