it sounds like the linkage needs to be adjusted, on the older sleds the one you need to adjust is horizontal right above chaincase not sure if the new ones are the same. Its really no big deal, it happened to me when i took off the trailer with no miles and once again at 800 miles.
You wwant to adjust that linkage to make it longer and it pulls the gear out more,(If the same as my 09)sounds like it is not pulling it out enough,but just enough were it tries to engage.