Clean accessible food residue and the surrounding sink area using the appliance's approved methods. Flies near the opening do not prove that the disposer motor is faulty or identify where they are breeding.
What the observation tells you
Check ordinary food-storage and waste-container hygiene as well as any permitted removable baffle. Do not pour pesticide, bleach mixtures or chemical unblocker into the disposer. Avoid reaching below the opening to investigate hidden material.
A useful next step
If the problem persists after appropriate cleaning, have the drainage and surrounding area assessed through a suitable service. Report slow drainage or recurring odour separately so a hidden water-path issue is not overlooked.
Manuals and supporting guidance
Model-specific instructions take priority. These references support the practical principles discussed here; they do not diagnose your appliance.