I have an 06 Explorer that I bought just a few months ago. Gently used - only 25,000 km on it - in great shape.

All of a sudden, just the last week or two, I am having trouble [occasionally] pushing in the button on the shifter when it's in park. It shifts fine, and there is no problem going to and from reverse or any forward gear.

I thought I wasn't braking firmly enough, orenough in advance of pushing the button. But even when I pay enormous attention to pushing the brake hard before even touching the button, it still is sometimes a problem to push that button in. I thought maybe the wheels were turned too tightly, but that doesn't seem to be an issue. And it doesn't happen every time.

Would anyone have any idea what might be causing this? Thanks