Dewalt DCFS950 Fence Stapler Fail to Fire Issue 

I want to oil it so bad but DeWalt says to not oil them anywhere at all which is crazy to me

I use a bit of silicone spray that dries away to nothing for the nail rail and tip parts of my dewalt framer. Doesn’t take much dirt to stop the nails from feeding. I just spray it down and polish it dry. Oil and plastic aren’t a great combo, but the silicone spray seems to work fine. That’s just me though. Lol If you look up something like wd 40 specialist quick dry silicone spray, it says safe for vinyl, rubber, and plastics, without any residue.

If you're still having issues, check for any loose wires & screws. Remove the cover on the trigger switch. Clean the contact, then take a small screwdriver and press or slightly twist the contact so it's slightly closer and better lined up. Give it a quick shot of electrical parts cleaner. Reinstall the switch cover. Clean the depth switch as well while you're at it. Reassemble. It worked for me.