A short programme may be unsuitable for some detergent products or levels of soiling. Check both the programme table and tablet instructions before interpreting a remaining tablet as a failed component.
Understanding this situation
Placement, a blocked dispenser area and a damp clumped product can also matter. The result should be described precisely: intact in the compartment, partly dissolved elsewhere or residue on dishes.
A useful next step
Use a supported product and programme combination. If the issue persists on appropriate loads, record those details for assessment. Do not remove the dispenser lid or put tablets in arbitrary locations to bypass the problem.
Manuals and supporting guidance
Model-specific instructions take priority. These references support the practical principles discussed here; they do not diagnose your appliance.