2010 JKU automatic: having occasional issues shifting out of park
 

This has been a reoccurring issue with my 2010 wrangler unlimited with 3.8L V6 and automatic. Sometimes I can go days with out having an issue, and sometimes it happens every day.
This morning was the worst occurrence I've had, so before it get's worse I'm trying to figure out what is going on. Basically when I get in the jeep, I start it, then go to shift into reverse or drive, and the shifter won't move back to that position. I almost feel like I have to really cram down on the brake pedal then it will shift, but I really don't think that's the issue because I'm triggering the brake lights with very little pedal travel and there is only one switch. Today I started it and it wouldn't shift, no matter what I did. I pumped the brakes, stepped down hard, shut it off and tried it all again but nothing. Finally after jacking with it for a few minutes it shifted and I didn't have any more issues at all today. So does anyone know what I could be missing??Thanks,Clay