A clogged dryer exhaust is a fire hazard. The dryer exhaust hood should never be clogged or blocked. The exhaust must be free and clear of blockage or restriction. It requires regular maintenance.
This dryer exhaust has a screen on it. Screens are not permitted. They clog up with lint and hair.
After cleaning, check to make sure the damper is installed and operating properly.
Use a camera and take a picture of the dryer exhaust pipe. Make sure it's clean.