Maybe try a third party USB-C to HDMI 2.0 adapter? These computers also support 60Hz refresh rate over HDMI when used with a supported HDMI 2.0 display, HDMI Premium Certified cable, and a compatible third-party USB-C to HDMI 2.0 adapter. The MacBook (2015 and later), MacBook Pro (2016 and later), and iMac (2017 and later) support these resolutions and refresh rates over HDMI 1.4b when using the USB-C Digital AV Multiport Adapter with macOS Sierra 10.12 or later: You can use 4K displays and Ultra HD TVs at the following resolutions and refresh rates via the built-in HDMI port of your Mac:Ĥ096 x 2160 at 24Hz (mirroring is not supported at this resolution)
