3D printing is a relatively new way to mass-produce parts, and that comes with a slight learning curve on the part of both industry (how to make the machines reliable) and you, the buyer.
The issue comes down to this: I have heard that a single strand of dental floss will probably not work well pulling a car up a hill. Now, I know what you’re going to say: “crappy dental floss!”, or even “get a smaller car!” But in reality, the floss wasn’t designed to pull a car, any more than the 4CELNK-YR clips are intended to handle all cables in all numbers under any circumstances, in a blast furnace. They can’t do everything; they do what they do, and they do that well. If the clips can’t do what you want, well they can’t do what you want. It doesn’t make them defective, they’re just not made for that.
With that in mind, when opening the clips wide, they will often may make “crackling” noises, and there might be discoloration of the plastic on the inside edge. This is actually normal for this kind of 3D-printed part, and should not affect the part’s functioning once in place. I’ve tested them to just over 100 on-off-on cycles with no loss of function. But, like all plastic parts, they do have limits. If you’re worried, warming the part to ~140F (60C) can ease them over the tube better.
But, in the end, they’re plastic parts. A solid piece of plastic is not typically expected to operate this way either.
It all comes down to how a “Fused Filament Deposition” (FFD) 3D printer creates the part. When it lays down another thread, the hot plastic melts the nearby material and they “fuse” together. While this is a good strong bond, not all the threads bond perfectly well. Because the “inside” of the tubular thread is strong than the bonds between them, bending stress tends to loosen those between-thread connections long before the thread break.
The bottom line is that in cases where I’ve bent it badly enough that the layers came apart on the far side (away from the cables), the clip still worked and held on just fine. Yes, it needed more bands to keep it in place, but it certainly wasn’t “broken” by any means. I suspect you’ll find the same.
Happy (Gentle) Snapping!