I get a dryer exhaust smell in the house when it is running, even though it is still venting warm moist air outside. This situation has just started in the last few days. What to do?

The dryer duct can still partially disconnect somewhere between the dryer and outside vent. I've had that happen on mine as well.

Won't happen again however.

Look first at the back of the dryer. Make sure it hasn't come loose there.