Bottom of fridge always full of water

Question

My liebherr bottom freezer refrigerator constantly has a pool of water in the fridge. I have tried cleaning the drain - makes no difference. Today there is ice on the back wall - which is not always there so maybe the temperature fluctuates, the ice turns to water and drips to the bottom of the fridge . The dial indicates that the fridge has a setting of 1 - out of a possible 4 - so cannot turn it down - any ideas?