Wifi stops working when connected to switch

[mayureshbhagwat]

I’ve a dumb switch that has Airtel router, sophos firewall in ha mode and then core s switch connected to it.
With this connection in place, the WiFi simply stops working. If I disconnect the airtel router from the switch the WiFi starts working normally. Any help in this front is highly appreciated.
PS: when I say Wifi stops working, it means users lose Wifi connectivity and are unable to associate over wireless though it’s visible in available networks.

 

[Aashish.007]

Is there conflict in IP ranges somehow, is there other dhcp on the network?

 

[mayureshbhagwat]

The answer would be yes and no. The sophos firewalls are in active passive mode. Tried changing the switch but didn’t help either.