Delivery exception usually occurs when they attempted to make a delivery and nobody was home to sign for it. This could be a different scenario.
Someone was home and it had on the detail column, "Customer not available or business closed." Which is totally BS.
It could also be a misunderstanding, like if you are in an Apartment or other area.
I have had issues with FedEx drivers in the the past faking Delivery Exceptions, my house is a bit out of the way (Apparently) and drivers like to skip it on busy days. I would make a call ASAP and call them out on it. It could also be a misunderstanding, like if you are in an Apartment or other area. But yes, just call FedEx.