You have to start with finding what IP address (use a IP scanner AP on your laptop/mobile while you are connected to the network) your 2nd AP is getting. Once you know the IP, try to access it and check what version is running on it.
AP should be on same IP subnet as master and should be on 200.x version, in order to adopt automatically by Unleased master.
If AP is on different version than 200.x, you have to manually upgrade it.
Syamantak Omer | Community moderator | Staff TSE | CWNA | CCNA | RASZA | RICXI | Follow me at https://linkedin.com/in/syamantak-omer-5949b6124