The M1 Adapter needs the InstantView app from Silicon Motion to run both HDMI ports for multiple displays. Without InstantView, only one HDMI port outputs video.

macOS (Catalina through Sequoia):

1. Download and open the macOS installer.
2. Run the installer from the .dmg file.
3. When prompted, grant permission in System Settings > Privacy & Security > Screen Recording.
4. Restart your Mac after installation.

Download the macOS InstantView installer

Windows (10 and 11):

1. Run the InstantView .exe installer and follow the prompts.
2. Restart your PC after installation.

If you need the Windows installer, contact Satechi support.