I had the exact same thing happen with my 21 a few months ago. Took it to the dealer to get checked out. They did a pressure test etc. Everything checked out 100%. Had them change out the original battery which was getting weak. No problem since. I'm convinced it was a voltage issue.
Last August, squirrels chewed some wiring above the gas tank on my ranger, and light wiring on my trailer. I drive the Ranger daily, so it's not like it sat undisturbed for any length of time. I've shot 26 squirrels and counting since last August. ?
Don't know if this will help you. I've got them on my fx4. Unloaded there's about 3/4 -1" clearance between the spring and the timbren. Maybe you could use a spacer on top to adjust the space. They are great for towing or a heavy load.