API concurrent access

It seems that PVE API doesn't address well multiple concurrent requests of container creation. launching a playbook on a group of three LXC to be created, I obtain:

 ____________________________________________________________
/ TASK [cielito.proxmox.create_lxc : Create LXC from scratch \
\ in Proxmox node | Token]                                   /
 ------------------------------------------------------------
        \   ^__^
         \  (oo)\_______
            (__)\       )\/\
                ||----w |
                ||     ||

[WARNING]: The value '' is not a valid IP address or network, passing this value to ipaddr filter
might result in breaking change in future.
[WARNING]: The value 'False' is not a valid IP address or network, passing this value to ipaddr filter
might result in breaking change in future.
[WARNING]: The value '' is not a valid IP address or network, passing this value to ipaddr filter
might result in breaking change in future.
[WARNING]: The value 'False' is not a valid IP address or network, passing this value to ipaddr filter
might result in breaking change in future.
[WARNING]: The value '' is not a valid IP address or network, passing this value to ipaddr filter
might result in breaking change in future.
[WARNING]: The value 'False' is not a valid IP address or network, passing this value to ipaddr filter
might result in breaking change in future.
fatal: [ni.cielito.uy -> mate.interior.edu.uy]: FAILED! => {"changed": false, "msg": "Creation of lxc VM 134 failed with exception: 500 Internal Server Error: CT 134 already exists on node 'carpincho'", "vmid": "134"}
changed: [xi.cielito.uy -> carpincho.interior.edu.uy]
changed: [pi.cielito.uy -> carpincho.interior.edu.uy]

and 134 is the PVE host number of pi.cielito.uy, just created by the same playbook.