I have faced the same issue in this post.
https://stackoverflow.com/questions/749 ... f-commands
I setup a mesh network using nRF Mesh android app with 3 nodes: 1 node with onoff client model (named cli1), 2 nodes with onoff server models (named srv1, srv2 correspondingly).
1. To control led on node srv1, I must press Connect button in the app and select node srv1. If connecting successfully, then I can control leds on/off (already binding app key) on node srv1. At this time, if I choose node srv2, then I can't control leds on srv2.
2. To control led on node srv2, I must press Connect button in the app and select node srv2. If connecting successfully, then I can control leds on/off (already binding app key) on node srv2. At this time, if I choose node srv1, then I can't control leds on srv1.
3. If I press Connect button in the app, and select node cli1. If successfully, but I can't control leds on nodes srv1, srv2.
In my understanding of BLE mesh, if the app connects successfully to one of 3 nodes within a mesh network, then I can control leds on all server nodes in that mesh network from the app, or any nodes.
I use 3 boards with ESP32-C6 chip, esp-idf 5.4.1, in Arduino environment using NimBLE host stack. I follow 2 tutorials:
1. https://github.com/espressif/esp-idf/tr ... off_server
2. https://github.com/espressif/esp-idf/tr ... off_client
Here are my 3 boards: 1 board with blue led is OnOff Client node, the other 2 boards are OnOff Server nodes.

Thanks.