A disposer processes suitable food solids; it does not remove fat from wastewater. Keep cooking oil, melted fat and greasy pan residue out of the opening and use an appropriate household waste route.
What the observation tells you
A sink can look clear immediately after hot greasy liquid disappears while deposits build farther along the drainage. Adding detergent or running the motor longer does not provide evidence that the pipes will remain clear. Cold water during ordinary grinding is not permission to pour in solidified fat either.
A useful next step
Collect grease separately and wipe appropriate cooled cookware before washing. Recurrent greasy drainage restrictions need the pipework assessed.
Manuals and supporting guidance
Model-specific instructions take priority. These references support the practical principles discussed here; they do not diagnose your appliance.