Water Level Sensor ADC121C021-WL

The sensor appears to have two settings of 12 or 300’ish. When dry it reads 12, when barely placed into water to jumps to the high number of 3300’ish. There appears to be no middle ground or ability to read a level; sort of a binary water detector as it stands.

So, what have I missed? The ADC code (Feather HUZZAH) is very simple and data is being received. Any ideas?

can you share the code you are using in this test.