Humidity sensor aspiration has been shown to accelerate sensor aging. Is this guaranteed to happen 100% of the time? No! However, you have to consider it when troubleshooting your issue. If you have eliminated aspiration as the cause of your sensor problem, then move on to the next thing.
I think you are probably dealing with a moisture problem unrelated to aspiration. As Sensirion even states in their documentation, the sensor will show a wet bias after a high humidity event. However, they also say the sensor should slowly recover from it over time. I don't think the recovery is happening as it should.