Give the installer the chronology before attempting an appliance repair. A dishwasher that drained normally until the waste connection changed needs the new arrangement checked alongside its own operation.
What the observation tells you
Optional disposer inlets and connection kits have model-specific preparation requirements. That does not justify opening an inlet or removing a plug yourself; an incorrect intervention can create another fault. Keep both model numbers and the installation paperwork available.
A useful next step
Describe the dishwasher's observed drainage behaviour and any error display. If the sink backs up or a connection leaks, stop use of that route pending assessment. New installation work needs the appropriate installer rather than a generic disposer reset.
Manuals and supporting guidance
Model-specific instructions take priority. These references support the practical principles discussed here; they do not diagnose your appliance.