Dyson Humidify+Cool Deep Cleaning Cycle Error Won't Go Away

I purchased a Dyson Purifier Humidify+Cool Formaldehyde air purifier on 23.05.2024 with the invoice number B012024000420121 from Dyson Turkey Online. Some time after the purchase, a “Deep Cleaning Cycle” warning started to appear on the device display. Although I carefully followed every step in the user manual, the deep cleaning cycle, which should normally last about one hour, stops after roughly 10 seconds and does not continue. If I leave the device like this, it behaves as if it has completed the one-hour cycle over the course of several days, but in reality the cleaning is not performed and the process is not completed. When I reinstall the filter and turn on the humidification feature, the same alert appears again and demands another deep cleaning cycle. Because of this repeated fault, I cannot use the humidifier function at all and the product has effectively become unusable for its intended purpose. I was abroad for a while and wanted to use the product again when I returned to Turkey, but I saw that the same problem continued and that the device was not functioning properly. Although my product is currently out of warranty, my research shows that this deep clean cycle fault is a common and chronic issue reported by many Dyson users around the world, which makes me think this is a production-related defect rather than user error. I kindly request that my device be considered as defective and that a suitable solution be offered despite the warranty period being over. I expect my product to be repaired free of charge or replaced with a new one, and that I receive the necessary technical support so that I can use the air purifier and humidifier functions safely and without interruption.