Wireless is the problem. There's something in the environment that the receiver thinks is the transmitter. You can prove this by wrapping it completely in some aluminum foil. If that stops it, it's some kind of interference. If not, then the receiver is faulty.
If it's interference, it's not really a malfunction any more than it breaking when you hit it with a hammer is a malfunction. It's just one of the possible problems you may have when you decide to go with wireless.
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Work: the 8 hours that separates bike rides.