DHCP Option 43 is not deliverd by DHCP service

Hello everyone

Sophos XG SFOS 17.5.5 MR-5 in use.

We have Huawei AP's and one AC in our environment in different subnets. 

I have added a DHCP option 43 in console using following command to make the AP's in a subnet work:

system dhcp dhcp-options binding add dhcpname Blabla optionname Vendor_Encapsulated_Options(43) value '0104XXXXXXXX'

By using 

system dhcp dhcp-options binding show dhcpname Blabla

the following output will be shown.

Options Configured from GUI

---------------------------

Domain_Name                                                 

Subnetmask                                                  255.255.255.0

Default_Gateway                                             X.X.X.x

Domain_Name_Servers                                         X.X.X.X

Options Configured from CLI

---------------------------

Vendor_Encapsulated_Options(43)                             "01040A00FA0A"

So it seems like the option code is configured and ready.

But if I request a new DHCP lease. The ACK-Packet does not contain the DHCP Option.

Do I need to restart the firewall? Any idea how to get it to deliver the DHCP option?

I appreciate your inputs

Cheers Yanick