There are limitations in CEC re. # of players, recorders etc.
You can only have two Recorders, and three Players by default I believe. Then you have to change the LA manually (which Kodi allows for example) to a free address. However I think if you do this, some functions may not work as expected because some devices on the bus will expect a different role depending on the address.
Address Device
0 TV
1 Recording Device 1
2 Recording Device 2
3 Tuner 1
4 Playback Device 1
5 Audio System
6 Tuner 2
7 Tuner 3
8 Playback Device 2
9 Playback Device 3
10 Tuner 4
11 Playback Device 2
12 Reserved
13 Reserved
14 Free Use
15 Unregistered (as initiator address) or Broadcast (as destination address)