Cabin fan stops working after car is parked in sun

I have a W204 Mercedes where the cabin fan (fan for heater, and aircon) recently started to not work in specific situations.

In the morning when engine and everything are cold, the fan blows fine, at low setting all the way to highest; air conditioning works too.

Once I drive in hot weather, then park and switch off, switching the car on right after results in the fan not working at all. All the way from low to high setting.

Once I park in shade for some hours, or overnight, the fan will work again.

Has anyone experienced this before? Im guessing the issue is with the blower fan? What could be wrong with it?