What are the version and build numbers of your server, device agent and device firmware?

Is your server implementation a brand new one? Or is the implementation working with existing or old devices with no problem but becomes problematic now for all or for some of the device brand(s)/model(s)?

I reckon you also cannot other actions such as lock device or revoke/install profile on a per-device basis. If not, please give more details on various test results for each problematic device brand/model/firmware/agent combination.