When adopting a UniFi device with the Layer-3 SSH method, it enters ADOPTING state, but disconnects a few minutes later.
The set-inform command must be issued twice. Otherwise the device will disconnect after appearing to adopt. The process to adopt via SSH is the following (see more details in the Related Article below):
1. Issue the
2. The device will appear ready for adoption in the controller. Click Adopt.
3. Wait for the 'Adopting' status to appear on the UniFi controller, then issue the
4. The device should now change to a 'Provisioning' status and then to 'Connected' shortly thereafter.