When things disappear with me, I usually blame the fae and offer milk and honey! Lol My daughter loves pixies and I swear she draws fae to the house!
But I doubt that is your problem. You see, although your conscious mind steers the vehicle (you) the subconscious mind is the engine.
Even with pixies, and spirits in general, when things "disappear" it isn't that they are gone but merely that we cannot see them. Perception is very tricky. Ever heard the saying "if it were a snake it would bite you?" This is how most magick and spiritual intervention works, by altering perception! And perception then becomes the reality, because that's all reality is, how we perceive things.
Let me go on. Your subconscious is very strong. So strong that we may say things we subconsciously feel but do not wish to admit to consciously aka "Freudian Slips". It is so strong that we can be conditioned to act, or react without thinking (without using the conscious mind). If you are a habitual person, most of your day is run by your subconscious!
Now going into the wands. There are two possibilities, either
1 a spirit or spirits, be them benevolent nature spirits etc, may be causing you to lose or break these things by effecting your subconscious. Do you get weird dreams or feel presences throughout the day? It could be sending you the message that you're wand isn't right for you. Or perhaps wands in general. Not everyone uses wands.
2 and the more likely case, is that you're subconscious which is apart of your higher self is causing you to break or lose sight of these wands. Perhaps wands aren't your thing. Perhaps you are not focusing on the right energy for them and they do not work well with your personality/style/energy. Perhaps you still have a hesitation or fear of magick or what you may do with it.
I would suggest meditating on the subject, and ask yourself why this is happening. Keep your mind clear, but don't push away thoughts, be open to any passing thought. It may be telling you something you already know ;-)
When I try to do something, and I continuously have opposition from myself, I take it as a message that maybe I shouldn't be doing it. This also includes consistently forgetting to perform a spell I desire to cast or a task I've been meaning to do. As I said, our subconscious runs the engine, never forget that!
I have the same problem, when Im making something magical, Im writing spells on piece of paper... When I stop feel it for a wile it dissapear... I must still feel it and pay attention to it, I must hide it to my room, to my desk drawer ^^