Some reason after I updated from unity 5.5 to 5.6, every model that i preview doesn’t to preview properly when i pan around them as in this youtube video:
This is a known issue, there has been a quick patch issued with this being fixed in it. Try Unity 5.6.1p1, you should find that it does not appear there 
That is my problem as well.
@WashingMachine , i didn’t start having this issue until i upgraded from 5.5 to 5.6.1