Possibly because the stick is on the guest or iot network?
By default dns redirect works only on the lan network, from the manual:
procd_fw_src_interfaces
This option allows you to override the interface (lan by default) which is used in the PROCD firewall redirects/rules the service creates if force_dns is enabled. Only needed if you have renamed or deleted your lan interface. If you indicate more than one interface, separate them by spaces.