I fixed it last night. The culprit was loose change (pennies, etc) which had fallen through the crevices in the compartment and made its way deep within the console/jump seat. It was rattling against metal structure.
The symptom I had was a constant rattle of the jump seat/console. With the truck stopped, turned off, and in a quiet area, if you lightly punch or jolt the console from the driver or passenger seat sideways and hear a metallic-like rattle, it is likely change that got trapped so keep reading.
I used the first 1 minute (no further) of the video below as a guide for taking the console apart. Disregard the first step of removing from truck, just start at the cup holder part taking out the insert. All disassembly took no more than five minutes and a Phillips screwdriver.
I’m convinced if you or anyone else has the exact same sounding issue, then this is likely the solution. In my case, the loose change was against the hinge part in the back of the console (the two large hinges shown at the 1 minute mark but deep within the unit).
I put in some felt material against the hinges so this won’t happen again. Sadly this unit isn’t the best design since change can easily fall from the compartment to deep in the console if you ever lift it up and use as a seat with change and small stuff inside.
Hope this helps everyone. I’ve confirmed no more rattles at all! Video of disassembly (only first minute needed as a guide):