Experiencing blurred fonts on a few windows and application.
When you use a high-DPI device such as a Surface Pro 3, Surface Pro 4, or Surface Book together with external monitors, you experience the following issues:
Although these symptoms may be seen on a single monitor, they're more common when you use multiple monitors that vary in display resolution. These symptoms also occur when the hardware configuration changes, such as when you dock and undock a device that uses external monitors, or you detach an external monitor from the device.
These issues commonly occur in the following scenarios:
Display information is determined when a user logs on to the system. A logoff-logon process resets the display information and improves behavior. However, the issue recurs if the monitor configuration changes during the same logon session, such as when you dock or undock the device or detach an external monitor.
This issue has become more prevalent since the introduction of 4k and higher resolution monitors, especially when these monitors are mixed together with older, standard monitors.
To resolve this issue, use the following methods.
If the issue persists, contact Microsoft support for further assistance.
You may also check Windows scaling issues for high-DPI devices (microsoft.com) for more information regarding this issue.