When it is through leveling that bright light should go real dim and on the diagram of the MH on the panel all the yellow light should be out indicating that it is level. Is that all happening? If the MH is parked on a level spot it may just take a few seconds to level.
Try reading the attached document. It has troubleshooting procedures and tells you how to adjust that sensor. My sensor is located in the basement overhead of my big bay on in the middle under the felt. I would read the pdf file very carefully on how to tell if the sensor needs adjusting or not because I doubt that it suddenly went out of adjustment. After you read the pdf file you may want to describe your problem again because that light is meant to flash like a strobe while it is leveling and will go real dim after it has completed leveling.
"Gunner" USN Retired, Airdale
2004 Monaco Signature 44' Conquest. Detroit 60