No. That "DHCP Required" checkbox would on apply if you client was trying to use its own address (not DHCP) and the policy manager state would be saying DHCP_REQD.
Since you are saying the policy state is 8021X_REQD, then that means the client hasn't even passed L2 Authentication (its not even in a state to get an IP address).
If a client is in 8021X_REQD, then there is no way it should be passing traffic...... So are you sure clients are passing traffic though the WLC says 8021X_REQD?
The WLC should never let traffic through the WLC untill you have passed L2 AUTH (which sets up the encryption), and then it should only allow a small subset of traffic untill you pass DHCP_REQD....
I seriously doubt an 8021X_REQD client is passing traffic....... Maybe if its HREAP and the WLC just isn't updating the state? But even that wouldn't make sense....
Perhaps you can do a "debug client " and several sets of "show client detail" over the course of a few minutes for a client in 8021x_Reqd. I bet after a few seconds/minutes that client is continually being deauthenticated....
