Apply global snapshot applies all automated parameters except Volume and Send level

With no automation in the project I can save a global snapshot, turn on preview in the automation panel, apply the snapshot and then punch all of the parameters and it will start writing automation to all parameters including volume and send volume. If I then take a second snapshot and do the same thing the send volume and volume no longer write automation. All of the other parameters for strip and inserts that have automation data written do punch correctly though.