DIAGNOSIS The robot's bumper or cliff sensors are getting caught on an overhang or the cabinet toe kick. It's a physical clearance issue.
FIX Use Keep Out Zones in the iRobot app. On the map of your home, draw a virtual barrier about 4-6 inches out from the cabinet base. The robot will treat that area as a wall and won't attempt to go under.
IF THAT DIDN'T WORK The robot might be misreading the shadow under the cabinet as a cliff. In the app's robot settings, try temporarily turning off "Cliff Detection" for a test run in that area only. Turn it back on afterward.
HEADS UP Keep Out Zones only work if your robot has created a saved map of your home. You need to run several mapping runs first.