Dropouts, the 100% meter, and that Performer settings have impact on recording sync indicate that routing on the Cubase end isn’t set up correctly. The VST Connect Cuemix plugin is often inserted in the wrong place (i.e. master channel…) It must be inserted in a group channel, and that group channel must be routed to the master output channel. This is because the cuemix plug is responsible for adjusting Remote Latency Compensation of the VST Connect system.
If you are still having problems feel free to drop me a PM so we can set up for a test.