Buick 2000 park Ave all AC outlets left side are 20 deg warmer than all on right

What is your question?

yesterday all was perfect, today all left side outlets, (when AC is on) that is defroster, ac in dash or air to floor are all about 20 to 30 degrees warmer (but not hot but not really cold, almost room temp) than all outlets on right, all right side outlets are correct and really cold all else is normal, ie, heat and all air flo move around normally heat appears to be normal temp left to right but I am not sure I can tell exactly Right side dash fine adjustment for right side air temp is neutral and never moved No recent work done or battery disconnect

How long has your 2000 Buick Park Avenue had this problem?

today