We can kindly confirm the following information upon testing: 

• Supports 4K at 60Hz when connected to an HDMI to USB-C cable.
• Supports 6K at 60HZ when connected to a Thunderbolt cable.

If your monitor is not reading the 60Hz refresh rate, you may need to manually adjust this in your System Preferences > Display > Refresh Rate. 

We hope this information has been able to provide a bit of clarification and guidance. 

Please feel free to reach out to us if you were to have any inquiries!