There are several possibilities for the humidity display to appear 100%RH in the climatic chamber, just check them one by one to solve.
1.Check if the temperature sensor and humidity sensor are installed opposite to each other.
2. Check if the gauze is hung on the chamber temperature humidity sensor. The sensor near the sink is humidity sensor. The gauze should be hung on the humidity sensor and wrap around the sensor's temperature sensing part.
3. Check the gauze after the gauze is placed in the correct position, to see if it can absorb water normally, whether the gauze is wet, whether the bottom end of the gauze is immersed in the sink, whether there is water in the sink. Please check and exclude above points one by one. If the problem is still not solved, continue to check following suggestion, if the gauze does not absorb water, change the gauze.