Relay functionality Mesh SDK v2.0.1


I'm working with simple_message_model using light switch example from  Mesh SDK v2.0.1, I have 4 boards nRF5832, 1 client, 1 provisioner, 1 relay node and 1 server which have the ble_nus project combined with my message model. The communication between client and server works fine but when I add relay node which is a server that have a relay functionality enabled, it doesn't relay my messages, I tried lowering the TX power of all the devices but it appears that the range is smaller and communication won't happen between the nodes, I ve looked into the network.c file and found that should_relay() function is responsible of whether relaying or not the packet, there is a condition that It should relay to a non unicast address, which is not my case, I want to relay it to my server which have a unicast address so I changed that condition, and still won't relaying, I don't know why ? is it because I'm sending string messages? Or something related with addresses and how they are assigned by provisioner (in order) because in my case they are not, I have relay node having 0x0107 address and server node with 2 elements assigned with these addresses 0x105 and 0x106.

Any help please, it would be greatly appreciated.

Thank you,