If those errors report at the same time. The second error might be triggered by the first one. Did you try to run the anyconnect on the server via a remote desktop? What if you managed to log on to the server directly and try again?

Agreed that the Z3 will not assign the same IP to a different mac address. But if the android device could use the IP it like even if it's duplicated with others. You cannot block a device to connect to an SSID. The block policy only applied after it...

Client VPN IP assignment is not using DHCP. So it cannot reserve the IP address