I recently purchased a used 2011 Kia Sorrento. After a week or so when I try to switch from park to drive or park to reverse the gear shift gets stuck and won't move even if you give a little force. I have to put it back in its original position and try again for it to work.

I'll be getting it fixed by the dealership since it's still under warranty but this problem only happens once every other week or so and I'm worried they won't be able to fix it because they can't replicate the issue. What could the problem be? Can the problem be troubleshooted and fixed without replicating the issue?