Excessive water draining from portable A/C

Question

We have a Maytag portable air conditioner that recently has been draining water out of the back of the unit (onto the floor). This occurs when we are running it in A/C mode. We don't run it in fan or dehumidify mode.We have had this unit for several years now and we did not have to drain the unit except once a month or so. Now, we have to drain it several times a day.It's almost like the unit is running as a dehumidifier, but it is cooling the room fine and sounds ok.Please advise. Thanks, in advance.