A damaged arm can affect how water is distributed and may behave differently from a simple loading obstruction. A visible split should not be patched with household adhesive.
Understanding this situation
The part's shape, openings and fit are specific to the appliance. A nearly matching arm or an improvised repair may not preserve its intended operation.
A useful next step
Use the full model for correct identification and keep the appliance unused where damage makes operation uncertain. Report the cleaning pattern and visible condition. Do not drill, glue or tape the arm and test it through repeated cycles.
Manuals and supporting guidance
Model-specific instructions take priority. These references support the practical principles discussed here; they do not diagnose your appliance.