Water collecting and freezing below deli drawer.
There are one of 2 possibilities that will cause the issue that you are having. The first would be that the defrost drain in the refrigerator is clogged and you would need to get it unclogged. This would be done by removing any ice built up in the drain trough then flushing the drain with hot water. The drain is located behind the cover on the back wall. If the drain is not clogged then you will want to look at the water tank located behind the pantry drawer for leaking.