I downloaded the source package from this website and used that instead of going through the asset store. Also this issue occurred in 1.6 on 2018.3, but not in 5.6.6.
So to be clear:
Unity 5.6.6 + 1.6 BD = issue does NOT happen.
Unity 2018.3 + 1.6 BD = issue happens.
Unity 2018.3 + 1.6.1 BD =...