2005 Buick Terraza Side door alarm

My van has had intermittantly developed a problem with the driver side power door. The door will not close at times. It seems like the door isn't recognizing that it's closed. The motor attempts to keep running and then opens the door back up. I can turn the power off to the door via the switch and close the door manually and it will latch. Manually closing the door causes another problem though. The door open alarm, beeping will continue to sound even though the door is latched closed manually. The door ajar alarm will sound but there will be no indication in the information section on the dash. I tested to see if the door ajar works on that door when it's actually open and it does indicate on the dash.