Does an unchanged stain prove mould returned?
Describe whether you see new growth, changed wetting or old discolouration. These observations need different consideration rather than one assumed diagnosis.
Why keep an earlier repair date?
It helps relate current observations to what changed. Identify the repaired component as well as the date if known.
Can I simply request the same treatment again?
Explain the recurrence first. Accessible inspection and moisture findings may support a different next step or additional scope.
What if one corner improved but another did not?
Keep both positions identifiable and describe each change. Improvement at one surface does not settle the other concern.
Should I repaint before the enquiry?
Describe the existing finish and previous work. Do not conceal or disturb the affected area merely to prepare photographs.
Does regular cleaning prevent another recurrence?
Routine household work has a separate purpose. It should not be treated as mould remediation or a guarantee while moisture concerns remain.