I had the same problem with the stripped blend door on the HVAC box. I was determined to find an alternate fix other than $3000 to replace the box. I designed and 3D printed a piece that would go into the remaining not stripped part of female spline (there is about a 1/4 to 1/2 inch behind the stripped part.. It worked until I went in the car twice, without starting it. it seems the engineer designed it always go towards cold as a zero point,, so if its doesn't stop it keeps going after entering the car. You dont even need to start the car. It moves when you open the car door. The torque is enough to snap my PLA plastic 3Dpart. Thats why the glue and tape doesn't work long,, the actuator continually will go towards cold past the blend door stop point. So in conclusion I made a design that fits in there and will slip when the torque is high, and stay locked in when its enough to turn the blend door. It is working perfectly. So now Nissan is not getting a $3k repair from me for their Bad Engineering. I have a 2018 Rogue. Bought for business trips, there is no question this is an Engineering flaw Nissan should take care of. But since its not a safety issue I suspect they don't want the cost. This is not normal wear and tear that cased this. I'll take some pictures and post if anyone is interested in a alternate fix.