The same thing happened to mine. I was driving and my truck started to have a horrible turbo lag, then all of a sudden it would catch up and take off. I pulled over and saw that the entire CIA had separated from the collar/sleeve which was still attached to the horn. I was lucky that the clamp stayed on the collar. The whole CIA and air filter had slid down the air box about 2" to the point where the filter was resting on the bottom of the box.
I really tightened it up now, so I will check to see if I've warped the CIA, then call Banks and have them send me the new version of the collar. That silicone coating on the collar is quite slick feeling, so I can see how it can slide off easier than the OEM under the weight of the free float air filter. I almost put the OEM collar back on.
2017 Silverado 2500HD Z71 L5P