I suspect the issue is with the P1297 - Connection Turbocharger - Throttle Valve Pressure Hose. I attached the vacuum hose and turbocharger diagrams for your inspection. I would recommend using some brake cleaner and spray it around these hoses and listen for the RPM to raise and that should help locate where the leak it.
Here is a guide that will help with that. Let us know what you find. Thanks