First Off my dear responders the person that began the thread said he was towing with a Dodge Ram
1500 NOT a Ford F-150 and there is a huge difference between the trucks...
Let start again:
While the Ram may well have a payload issue because of the Hitch weight - the request for further info regarding the type of hitch system is required. You say you are using a Reese hitch - what does that mean: 1) just the hitch Ball, or 2) A complete weight distributions system with anti sway (for example a Reese Dual Cam System).
Who installed this? Yourself or a dealer? Since the AS is 2016 did you buy from an owner or dealer?
Would be very helpful to have a picture of your setup (AS hitched to the Ram if possible)
You can also visit the following link for a discussion on towing capacity - may be helpful --
how-to-determine-if-your-tow-vehicle-is-right-for-your-trailer/