In my case this is not about a switch from cruise to thermal mode. While in cruise it would go up and down on its own. I never had this before and only seen it since the upgrade to the latest version.

On Monday, June 22, 2015 at 4:22:02 AM UTC-7, Greg Delp wrote:
I want to clarify something just in case you don't realize it like I originally did not. The volumes for climb vario mode and cruise speed to fly mode are completely independent of one another. Even though there is only one vario volume slider in the menu section, the volumes for each mode are independent. If your volume is changing exactly the same time as the climb/cruise mode changes then that is your issue. That was never clear to me in the manual.