In some cases, it's possible that the latch mechanism underneath, needs to be adjusted. But that should be the last resort. You want the latch to be a tight as possible, but still be able to just barely get the ball in there. This ensures the most secure connection.
IMO, if you can just barely get it in place, that's perfect. Now that you've learned the trick (ball slightly forward, so the coupler is "reaching" for the ball), you're good to go!
thebrakeman ('70), DW ('71), DD ('99), DD ('01), DD ('05)
2004 Surveyor SV261T (UltraLite Bunkhouse Hybrid)
2006 Mercury Mountaineer V8 AWD Premier
Equal-i-zer WDH (10k), Prodigy Brake Controller