Kärcher Window Cleaner Leaves Streaks & Weak Suction

I recently purchased the latest Kärcher window cleaning machine, and I am extremely disappointed with its performance. It leaves streaks and marks on glass and mirrors, completely failing at its primary function.

Within the first week, the rubber blade became deformed after just a couple of uses. Additionally, the vacuum suction is weak, making it even harder to achieve a clean surface. I sent it to the service center, explaining the issues, but they only replaced the rubber blade and returned it with a "no issue found" note. The performance remains terrible.

I deeply regret this purchase—I should have gone with another brand. Kärcher, please take responsibility and provide a real solution!