For confidence have a think about how things are working. When we turn on the voice in IF we are asking the simulator to send another 200 or so bytes of information. The actual amount of information is next to nothing, less than the data in a network packet header.
Even so there's a batch of readings IF only asks for when the Voice is active. Since this is a prior unused request, It is a possibility that one is unstable in P3D. Or it is made unstable by the addition of an addon that I have not tested. If that's the case I cut it out until fixed by LM.
On my rig and with my testing it all looks very sound within P3D itself. Problems usually emanate from the addition of something added to the sim like a plane or an airport. Poor overclocking, missing textures, bad simconnect demands, misspelled paths, unclosed P3D remnants etc.
Remember from past experience that IF doesn't actually do anything other than press buttons of your simulator. It is always best to start problem solving from the other perspective, but remember that IF is requesting some new bits of information, not much since most was already available in IF.
