This may not help but I'll pass it along anyway. Twist-lock poles rely on friction between the inside of the pole and a plastic bushing on the end of the smaller diameter section. The bushing expands when the pole section it's attached to is turned. What I've seen happen is that the bushing gets enough dust, or aluminum oxide, or whatever, on it (even tho it's inside the pole) that there's no longer enough friction to either tighten the joint or hold it once is IS tight. If you can take the two sections apart you can clean out both the inside of the larger section and the expandable bushing. Unfortunately, some companies make their sets non-removable.
I had a collapsible hiking stick that worked that way. It got so I couldn't use it. A good cleaning fixed it until the next time it got enough dust inside.
If you can't fix it, you might try using a screw-type hose clamp to keep the pole at the length you want it.
It's never too late to have a happy childhood!
Lee, WU0V, and Courtenay, N0ZDT
2011 Rockwood A128
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