Change DPI Scaling (Windows) - SanLiteOSRS/SanLite GitHub Wiki
When using the SanLite launcher, SanLite uses its own DPI settings. Before making any changes, make sure you have installed the latest SanLite launcher. If you are unsure, simply reinstall the launcher. If that did not work, try the following.
Overriding DPI scaling

(If "System (enhanced)" didn't have the desired effect, try also "System" and "Application")