If your external monitor is not working through the USB-C Slim Type-C Multi-Port Adapter V2, the usual causes are a video adapter in the chain instead of a direct HDMI cable, or a host USB-C port that does not carry video. The HDMI port on the USB-C Slim Type-C Multi-Port Adapter V2 outputs up to 4K at 60Hz and requires a direct HDMI to HDMI connection.

How to fix display problems with the USB-C Slim Type-C Multi-Port Adapter V2

1. Seat the USB-C Slim Type-C Multi-Port Adapter V2 fully into the USB-C port on your MacBook.
2. Connect your monitor to the adapter's HDMI port with a high speed HDMI cable, using a direct HDMI to HDMI connection.
3. Switch your monitor to the HDMI input you actually plugged into.
4. Detect the display on your computer. On a Mac, open System Settings and go to Displays. On Windows, open Settings, go to System, then Display, and select Detect.
5. On a Windows computer, confirm the port supports video. The USB-C port needs to support USB 3.1 Gen1 or Gen2 with DisplayPort over Alt Mode and USB-C Power Delivery. A Thunderbolt 3, Thunderbolt 4, or USB4 port also works.
6. Try a different HDMI cable.
7. Connect the monitor straight to your computer without the adapter to confirm the monitor and cable work.
8. Unplug the adapter, wait a few seconds, then reconnect it and check again.
9. Set the right expectation on resolution. The maximum output from the HDMI port is 4K at 60Hz.
10. Use the USB-C port for charging only. The USB-C port on the USB-C Slim Type-C Multi-Port Adapter V2 is for pass-through charging and will not read or write to a storage device. Connect storage and peripherals to the USB-A ports instead.
11. Connect one hard drive at a time, and keep in mind each USB-A port has a maximum output of 5V and 1A, so the Apple SuperDrive is not compatible.