This is the remote latency which is required to compensate for the roundtrip delay.
You probably have enabled input monitor on the Performer track - don’t. You hear the Performer signal thru the Control Room VST Connect Monitor plugin at any time. If you listen via headphone in Cubase, you may have to move that plugin to the headphone monitor channel bottom.
You are advised to start an empty Cubase project and use the “Create VST Connect” function from the VST Cloud/Vst Connect menu.
More details can be found at https://connectvst.com