The Hyp smearing parameters for two level smearing shall be 0.3 and 0.6 rather than 0.6 and 0.75 for first and second level.
There are multiple reasons.

1. the minimum plaquette is decreasing for latter but is maximized for first case.
2. we shall increase number of smearing steps from 3 to 5 for first case for lower temperature configurations.

The problem with 3 smearing steps for lower temperatures is that signal is lost for very small values of R.