Sid, Light loads can be an issue in many inertia system semi auto shotguns. Break it in with heavy stuff. The more you shoot it the more dependable it will get with lighter loads.

They use a Benneli operating system so, that right there says a lot, getting a shotgun thats running a benneli system for under a grand sounds good in my book
"All Affinity autoloaders are powered by a version of Franchi’s parent company Benelli’s Inertia Driven operating system, the main difference being that the return spring straddles the magazine tube rather than being located in the stock. The result is a slightly weight-forward feel, which aids in swinging the shotgun. It also makes post-shoot cleanup easy.
The system is exceptionally reliable. In fact, despite shooting numerous birds, including ducks, geese, doves, quail and even turkeys with my personal Affinity 3.5, I can’t recall a single malfunction. "
That was from an online review by Grandview outdoors
grandviewoutdoors.com/shotguns/shotgun-review-franchi-affinity-3-5-elite

Sid, I had this issue with a similar Mossberg and had better success using a minimal of 1200fps rated loads. You can see what Franchi has to say about it by inquiring online here : franchiusa.com/contact-us