Thirs DHCP on Sophos not distributing IP-Adresses

Hi,

i have the problem, that the third configured DHCP-Server for a WIFI-Network does not distribute IP-Adresses to the clients.

First DHCP (WLAN1)
192.168.11.x (Working perfectly)

Second DHCP (WLAN2)
192.168.12.x (Working perfectly)

Thirs DHCP (WLAN3)
192.168.13.x (WLAN is found by the clients, but does not distribute IP-Adresses)

Every Setting in the 192.168.12.x is exactly the same as in 192.168.11.x and in 192.168.12.x

Sophos Version: 9.002-12

Can anyone help me please?
Thanks

Lars