Version 2016.3.1024.45 (from nuget packages, if that matters) Adding a new row with the "Add new row" button and then clicking the row indicator results in an extra row. Demo: http://recordit.co/Nn8y2z2YpI Available in the R1 2017 SP1 Release.
We have also run into this issue, and haven't found a way to avoid it
This is very annoying for our customers