Yes. A format misunderstanding can produce a much longer or shorter programme than intended, so check the separators and units before pressing Start.
What the observation means
Some interfaces change format as the duration increases. A pair of digits may therefore mean different things on different screens. The manual's timer example is more reliable than interpreting a colon by appearance alone.
A useful next step
Cancel an unintended duration using the normal controls and verify the corrected setting. If food has already been held or cooked under uncertain conditions, follow appropriate food-safety guidance. Include the displayed format in an enquiry if the timer counts differently from the manual's description.
Manuals and supporting guidance
Model-specific instructions take priority. These references support the practical principles discussed here; they do not diagnose your appliance.