Air Purifier w/ Quality Sensor 970 Sqft

First of all I love this Air purifier, it's intuitive and though loud on higher settings it doesn't run high often. Now... Filter changes aren't intuitive and reset is challenging, I have dogs, vacuum frequently, and filters need replaced more often than I'd hoped. After about 4 months of use, a filter replacement and reset the sensor must be bad as it has been stuck on "10" ever since. Have not been able to get help from customer service or resolve the issue. Don't know if it's a simple dirty sensor or a bad one. It seemed to work very efficiently and effectively when functioning but now I can increase or decrease the fan, there is no auto mode any longer due to this sensor issue. Would not recommend this brand to others though I was very impressed initially.