Approach R10 indoor distance under

I have the Approach R10. the device is upgraded to the latest version. But it understates the distances. 

Setup in garage 4m to impact screen, and I have upto 3m behind tee position. The guide says 1.8m to 2.2m so tried from 1.5m to 2.5m still no difference. 

It makes it so hard to play E6 golf as I have to use a driver instead of a 5 iron. And it takes more than regulation to get to green.

Have tried adjusting altitude in game to increase the difference. It helps. But are garmin sorting the problem with an update. (Toggle in app indoor play.??)

I also have optishot which allows a + % to figure to meet what you get at the range or on the course.

Typically 8 iron on range or course 140-150m depending on ground conditions.  I door R10 reads 100-110m