Are you running an android device with the simulator?
The simulator controls are laggy with the android version of the Go app on my Nexus 7, while it's nearly instantaneous response on iOS on my iPhone 7. So it seems the response lag may be an android issue, and it's ironic because apparently even DJI's own built-in display on the P4ProPlus controller (and likely the upcoming crystal sky displays) have latency issues too at least with the Go's simulator, as shown by this guy's review of the Phantom 4 Pro Plus - fast forward to 10:06. Crazy lag on the android version.
Yes I am using a Nexus 6P. It works perfect otherwise with the DJI GO app.