I have a 2000 Disco 2, a couple of days ago I noticed my shifter was stuck in park. I kept trying it over and over and finally, it shifted into reverse and no problem going into drive. I experienced the same issue a few times now. It gets stuck in park and then finally shifts. I checked the brake lights and they are working, could this still be a brake light switch, even though it's intermittent?

 

The shift solenoids are known to fail/ have issues. I would pull off the shifter cover and inspect for any kind of debris in the shifter mechanism, if all is clear, it would be wise to check the shift interlock solenoid and see if it is obviously suspect or if it is having problems retracting sometimes. Your best bet to make sure the brake switch is working is to watch for the brake lights coming on when this issue is happening. If they are working, odds are the switch is just fine