The only gears on a 2011 that require effort are 1st, when downshifting from a rel high speed (20-30mph) and reverse (bc of the square cut gears). One misshift isnt going to hurt your transmission, unless it was very bad and you have chunks of metal flying around in your tranny but from what you've said it might just be something with the synchro on 4th. Def have the dealer look at it and don't let them talk you into paying anything if your still under powertrain 36k.