I have a Jabra Pro 9470 headset, which has been excellent. 

A few months ago, pretty much overnight, I noticed that people were complaining that if I walked away from the base unit in my office, they couldn't hear me and I was cutting out. 

The supplier has no idea and suggested a new battery (significant cost), even though the battery seems to be lasting a pretty long time. 

I don't see any other changes in my configuration or layout so I am trying to determine what could be the issue and how I can fix it. 

It's an expensive unit I don't want to replace unless it's absolutely required.