[ZWAVE] Problem with mesh network

i’m so sorry but really don’t understand how works my zwave network.
This is my network:

All the devices are in the group 1.
But some device doesn’t join correctly in the network.
For example node 19 was added to extend the network: is very close to node 1 but doesn’t associate correctly.
Node 20 is about 3 meters to Node 22 outdoor, boot doesn’t connect togheter.
Really make difficult to understand why happen this.
What can i do to fix the network?