Only reading about 70% of my shots

Maybe electrical interference check out the thread forums.garmin.com/.../disturbance-due-to-electrical-devices

I do have a fan that is wall mounted in my garage it is behind the unit though about 8ft above the garmin. 

Watch your light on the garmin... if you are at address and the light wont stay green it's getting interference.  I had this problem with a fan where it would bounce between Green & Red...

Try turning that fan off even if you dont think it's the fix.   

Mine does the same.  Seems I have to turn it off and on about every 2nd hole or so.  I wish the status lights would tell you if it's not going to pick up the shot so you don't waste swings, in my case it'll pick up only the bad shot.

The only time it didn’t detect for me was when I pUTI reflective stickers on the ball as an experiment. Rest of the time it read every shot. Ensure set up is good and unit is a few inches above the ball.

you're lucky, mine is only reading 40-50% of my shots...and I tried all permutations.  I hit at the range, I moved the Garmin, in-out, different distances, leveled it, etc.  Firmware update, etc... still no go.  Plus 30% of what was recorded was way off, I hit a ball dead center with my driver at the range, it landed at around the 220 marker and it said it landed 180 with a 36 yard off center hit.  thinking of returning it for a Rapsodo or Mevo

I turned off my fan mounted on the wall behind the unit and have had better luck took 105 shots only had maybe 1-2 that did not read.  When I talked to Garmin support they said fans are ok as long as they are behind the device but I guess not.  Only tested once though will test again this weekend when I have more time.