Multiple Gateways are not supported on Q-sys cores.  This is at the Operating System level (Linux).   If more than one LAN port is being used, only one can have a gateway and the other should be blank or Beginning with firmware 8.10 you are no longer able  save network settings with two gateways.

IF you have a core with two gateways, you will need to delete one, save the file, pull the power on the core for 1 minute and restart the system.

Symptoms:  Chassis Fan errors, odd or irregular errors, VoIP disconnects, Switch_XML file(to Many file) errors, large amount of softphone registrations.