Join multicast group fail

[advancenXX]

I am using fastdds v2.7.0 and I find that,
fastdds : [Warning]Error joining multicast group on 192.168.42.128: set_option: Address already in use -> Function
update_network_interfaces
I am wondering what does it mean and what can I do to fix it?

[advancenXX]

-> create_participant
-> create_datawriter/reader/topic...
-> participant->set_qos(participant->get_qos()
-> create_datawriter/reader/topic...

I think the warning came up when set_qos() is called;