Dreame X40 Ultra Complete leaving dirt behind after brush replacement

Hi everyone,

I have a Dreame X40 Ultra Complete robot vacuum, and recently it started leaving dirt and debris behind during cleaning. I’ve already replaced the main brush, but the issue persists.

I’ve also checked the dustbin, and it’s empty. The robot seems to run normally otherwise. Does anyone have experience with this or suggestions on what else I should check (e.g. filters, suction power, sensors, or mop system)?

Thanks in advance!

Hello，
You can check whether there is wind blowing out of the air outlet during sweeping. If there is, it means that the fan is working normally.