2004 Honda Odyssey Parking slipping out of gear

2004 Honda Odyssey 45,000 miles

After I park my car and put the car into park, and turn it off. When I go to restart the car, it starts just fine, but then the "P" on the dash is not lit up, and I cannot shift it out of park. If I rock the car enough, I can get it to go into park, then I can shift into drive. If I put on the e-brake before I put the car into park, I do not have this problem.