Infortunatly the firmware update does not seem to fix all problems in combination with Intel HD4600 Graphics.
Users have not seemed to be bale to set the color to lower than 16Bits or 32Bits int he driver or Groahics Control Center form Intel.
This is necessary if you want to run 3840×2160 at 60Hz in 4:4:4 you cannot run higher than 8Bits and in 4:2:2 not higher than 12Bits. Otherwise the signal takes more bandwidth than 18Gbps which is the max for HDMI2.0.
You are welocme to try the firmware update, please send an email to [email protected] for that.