Why is my external monitor not working?
Luna Display and 4K+ Monitors: Connection Issues
If your Mac has an external monitor with a 4K or higher resolution and Luna's connection is unstable or drops in resolution, try disconnecting the monitor to see if the issue improves.
Thunderbolt Bus Limitations on MacBook Pro
On some Macs, like the MacBook Pro, Luna may not work correctly if plugged into the same side as a high-resolution external display. This is due to how MacBook hardware distributes bandwidth.
Solution: Plug Luna into a port on the opposite side of the MacBook from where the external display is connected.
Example: 2019 MacBook Pro
The 2019 MacBook Pro has four Thunderbolt 3 ports—two on each side. Each side shares a single Thunderbolt bus controller between its two ports.
Thunderbolt Bandwidth Conflicts
If a Thunderbolt or USB device is connected to the same Thunderbolt bus controller as Luna, it may consume too much bandwidth, preventing Luna from functioning correctly. This is common with Thunderbolt docks, hubs, or external monitors with 4K+ resolution.
M1 and Apple Silicon Display Limits
Newer Apple Silicon Macs, like the M1 Mac mini, have strict limits on external displays. For example, the M1 Mac mini supports only one display via Thunderbolt/USB-C. Check your Mac’s technical specifications to ensure compatibility.