Bathroom Exhaust Fan Leak Help

We have a bathroom exhaust fan that eventually leaks after heavy rain. It’s only happened on raining days & there’s no visible water damage on the ceiling. I’ve went into the attic and was unable to find any leaks into the attic. My guess is that the rain is entering from the roof vent and accumulating in the exhaust fan ducts until it starts to leak. Any local company recommendations that can identify what the issue is and repair it? Would this fall under a roofer or HVAC tech’s expertise?