Yes, it is perfectly normal to hear the fan running during and after your cooks.
The fan is cooling the Brava and its electronics. It's good practice to let the fan run instead of unplugging the Brava to stop the fan noise. To accelerate the cooling process, you can keep the Brava door open.
In rare situations, the cooling fan may turn on when the Brava is not hot. This is likely because the Air TempSensor in your Brava has moisture build-up and is falsely sensing air temperature in the chamber as too high. The sensor needs to be recalibrated. To do so, please navigate to Settings --> Utilities --> Air TempSensor Calibration.
The calibration will run a cook for 1 hour and then cool for a half-hour. After the half-hour of cooling, the Brava will check if the air temperature is within an appropriate temperature range. If is it not, the Brava will repeat the Bake process once more. This entire process takes anywhere between 1.5-3 hours.
This will recalibrate the sensor and your Brava should be back to a normal operating state. If the cooling fan still runs unnecessarily, run the calibration program one more time. If the problem persists, please contact Brava Customer Success at firstname.lastname@example.org.