This is neither a configuration issue, nor a bug. DFS operation is only defined in Access Point mode. In a mesh network environment you cannot properly implement DFS as specified by IEEE 802.11 since the channel switch mechanism mandated by DFS relies on a central instance (the access point) to issue CSAs.
If all nodes of a mesh would simply hop to a random channel upon receipt of a radar pulse, the entire cell would quickly break down. There is currently no standard way to support DFS in mesh or IBSS mode at all and there is also no proprietary solution I am aware of.