There are instances when a new USB-C device cannot be detected by your Mac. This issue can be caused due to different circumstances. Here are some suggestions to fix the issue.
- Try a different USB port to rule out a faulty connection.
- If you're using an adapter, double-check that it’s working properly and securely connected.
- On your Mac, go to:
a) System Settings > Privacy & Security
b) Scroll down to the Security section.
c) Under 'Allow accessories to connect' OR 'Accessories,' change the setting to 'Always allow.'
Your system may prompt you to enter your Apple ID password to confirm the change.
Unplug the mouse and test that it works. You may need to do a restart.