what is the gateway of that subnet ? and what is the gateway or default route of the contollers ? make sure those 2 subnets are having routes pointing to each other from the layer 3 device.
Start from the controller and move towards the gateway of the controller's IP and from their start troubleshooting... also check what role those clients are getting and if there is any deny rule matching the controllers IPs or subnet.
from those clients Can you reach or ping any other device from the same subnet as the controllers ?