When I noticed that the isolator on my CTX was staring to rotate a bit and shorten when I leaned on it the first suspect was that the soft carbon fibre was wearing.  Turns out it’s the cam-lock.  This can easily be solved by rotating it completely and looking for the worn areas that contact the lower wand–holding it steady.  I then put a thin layer of epoxy on these two areas to make for better engagement with the isolator.   Works well–nothing worse than a wiggly detector that does not stay at the length you set it to.  The epoxy can then be filed as needed.  Make sure that it’s moving properly before the epoxy sets!