I have a GC 2012 diesel and had a similar issue.
Problem s I have ascertained is that when parking that the front bumper actually had touched the garage wall. Sensor originally showed i still had one bar showing but actually touched the wall. No visible damage but driving next day square bezel around radar sensor moving causing error messages FCW / eTC.
After pulling plastic under cover off front bumper bar found that because of the light bump on the plastic front bumper their is 3 screws holding the radar sensor. They are easily popped as they are only held in by a plastic grommet which each thread screws thru. Unless checked and are firmly in place the sensor will slightly distort its level even with square bezel in place.
If you still get error messages FCW etc it is one of the 3 metal screws which are held in place by a plastic insert that hold the radar sensor is still loose- causes radar sensor to either pick up road to the left or right or elevation is down.
The parts look minimal- just a plastic grommet which one off the small screws screw into needs replacing.
Hope this helps -
Strategy from Australia