In sshd_config and firewall rules, you have to allow those IP to connect as root:

    Admin network:
    tulipe 10.1.0.4
    bkp-pa2-01 10.1.4.4
    bkp-pa3-01 10.1.0.11
    bkp-pa3-02 10.1.0.25
    bkp-pa3-03 10.1.0.29

    Public network:
    tulipe
      IPv4: 78.202.249.60 176.179.23.41 109.190.110.196 37.9.140.2 171.33.118.128
      IPv6: 2a01:e34:ecaf:93c0::2 2a02:e640:0:300::2
    bkp-pa2-01 37.9.136.68
    bkp-pa3-01 37.9.136.143
    bkp-pa3-02 37.9.136.130
    bkp-pa3-03 37.9.136.156
