Impossible to join primary node

[ShahriyarR]

Glad to see that, problem solved.
As i previously stated, there was some network (firewall, port, name-resolution, ip conflict) issue.
Exactly with 4444 port:

[Note] WSREP: Prepared SST request: xtrabackup-v2|172.18.172.145:4444/xtrabackup_sst//1