Loose fibres can become more visible against a contrasting fabric, especially after a lint-shedding load. The appearance should be distinguished from detergent marks or a change to the dye.
Understanding this situation
Review the recent sequence of textiles and the model's cleaning instructions. A few adhering fibres do not identify a failed heater, and a chemical cleaner is not automatically the right response to a physical lint issue.
A useful next step
Use an appropriate garment-safe removal method and the appliance's permitted between-load care. Keep known shedding items separate where practical. If deposits continue unexpectedly or accompany a warning, describe the material and load history to the service team.
Manuals and supporting guidance
Model-specific instructions take priority. These references support the practical principles discussed here; they do not diagnose your appliance.