Last week my VoxATC was playing up, or so I thought.
Anything I said to ATC was not being recognised the first time, but if I repeated it VoxATC would accept it on the second go and respond correctly.
It turned out that my microphone was playing up and VoxATC was actually not receiving anything that I said.
It took me a while to work this out as I had ruled out a faulty mic, figuring that if VoXATC heard me the second time the mic must be okay.
It seems that a little known (to me at least) feature of VoxATC is that if it doesn't recognise a message the first time, you can say anything the second time and it will accept it.
One thing the whole episode did make me realise was that, despite VoxATC's occasional quirkiness, flying without it is pretty pants now. It's become an indispensable part of the whole experience.