A completed programme does not guarantee removal of every stain under every product and programme combination. Cup material, old staining and the chosen treatment all matter.
Understanding this situation
This differs from food remaining everywhere or an unfinished cycle. The cup's own care limits still apply, so repeated intensive washing is not automatically appropriate for decorated or delicate items.
A useful next step
Use a suitable cleaning method and supported dishwasher programme. Describe persistent staining separately from grease, grit or detergent residue. If cleaning has changed broadly on appropriate loads, include that wider pattern rather than diagnosing from one old stain.
Manuals and supporting guidance
Model-specific instructions take priority. These references support the practical principles discussed here; they do not diagnose your appliance.