Ball Speed off by 10mph for driver

Ballspeed way down on driver.

My local driving range has had Toptracer for the past 5 years.

For the first couple of years, I was using my G80 and was quite surprised at how close they were in ballspeed, generally within 2mph ballspeed with the driver.

I'm up to my 4th G80 now, as when I'm working on my swing, I will use the g80, then sell it when I feel I wont be using it for a while, and then buy another one when I require another.

So lately Ive been working on a few things, and bought another g80.  My average ball speeds with the toptracer is 140mph, but this g80 is recording on average 10mph down at 130mph.

Yes, I have the correct distance to the ball etc, as this is not my first g80. Firmware was at 4.30 so updated to 4.50 but still same issue.

I thought, what the ***, this g80 must have a faulty radar, so guess what? I bought another one.

First time out, same problem. This recent 2nd g80 is the same as the previous one, and reading 130mph when the toptracer is reading 140mph. 

My other g80's that I purchased years ago, that may have had the older firmware was accurate.

The swing speed is pretty accurate, but gives me below than normal ballspeeds, which in effect gives me way lower smash factor. It was normal before to get 1.45 smash factor.

Now its 1.3 - 1.35 smash with the driver

Why would the newer firmware ballspeed be inaccurate?

Anyone else having this same issue with the latest firmware 4.50 ?