Only connect and use fixtures permitted for the exact model. A toilet macerator is not automatically a kitchen wastewater pump, and grease creates its own drainage concerns.
What the observation means
Temperature and waste composition matter as well as the pipe connection. Existing plumbing does not prove that the arrangement is suitable.
A useful next step
Keep fats and food waste out and identify the unit before further changes. If a kitchen fixture is connected, describe it when seeking assessment. Do not add hot water or chemicals to melt a suspected blockage through the system.
Manuals and supporting guidance
Model-specific instructions take priority. These references support the practical principles discussed here; they do not diagnose your appliance.