All self defrosting fridges have an evaporator pan or water dispenser pan the same thing.
As the frost and ice melt, the resulting water drips into a trough. The trough is connected to a tube that drains the water into a shallow pan at the bottom of the refrigerator. The water is then evaporated by a fan that blows warm air from the compressor motor over the pan and out the front of the refrigerator.
Your evaporator fan may be weak or faulty and not be blowing the warm air over the pan well. This would me the water in the pan does not evaporate fast enough and then after a week or two when it accumulates to high in the pan the water runs over the top.
So you have water on your floor every couple of weeks.
This is a tough place to work very tight quarters and really needs to be done with experience. Techs get their hands cut up in there too, if they are not careful.
To test and work on the evaporator fan is not a home handy person fix.
You may want to have a hands on tech do this work