I noticed when using GCC / Ghl Control Center with a scaled 4k screen with Windows 10 (maybe also other windows versions) - you should enable compability mode on GCC.

Right click on the GCC Icon -> Properties -> Choose the "Compability" tab - > Check the checkbox"Override High DPI Scaling Behaviour. and select System (Enhanced) in the dopdown menu below that checkbox.

In that way GCC show correctly with scaling.

Dont know if anyone has brought this up before, but might be useful for someone.