After my car was involved in a front end collision the front radar sensor has been acting up. The body shop and dealership did state they have cleared any codes and realigned the laser, but it seems to still have issues. One thing I have noticed intermittently is the range of the laser has significantly decreased where it only picks-up the vehicle in front until 1-2 car lengths and sometimes not at all. Also, it will pick-up on larger humps and slumps in the road and the slow vehicle down thinking there is another car in front. I have a pretty good memory and it wasn't acting this way before the accident. Would anyone have any suggestions on what might be wrong?

I had a sensor issue and it took a test drive for them to confirm there was an issue with it. You'll have to have them drive and reproduce the error. Consult did not detect this in my case. Even on the "furthest" distance setting, my car would rear end the car ahead of me if I did not intervene.

I hope you're still under warranty or that the repair is covered under insurance due to the collision. A new sensor itself is $2200 IIRC. Mine was just out of warranty and I had to call Consumer Relations. They agreed to pay for the part and i had to cover $200 for labor.

Here's the thread that I started a couple years ago:
adaptive-cruise-control-t594512.html

I would have it calibrated one more time. After that its almost certainly the sensor. Make sure the responsible insurance knows right away that there is an issue with the previous repair.

If you are taking it to the dealer I would try to find a stretch of road or parking lot close to the dealership with features that cause the sensor to incorrectly react. That way it will be easier to reproduce the issue when the service writer and/or tech road test it with or without you.