Name which fan is heard
A cavity fan behind the rear panel and air leaving above the door are different observations. Describe the location and duration already noticed.
Explain the change
Include the length and type of cooking and whether the control was actually turned off. Model-specific assessment can distinguish expected cooling from a control or fan complaint without setting a universal time limit.
A useful distinction
A cooling outlet may continue moving air while a rear cavity fan has stopped. Naming the location avoids combining two different functions, and prevents a normal cooling sequence being described as a fan that will not switch off.