Hi Kevin.
In some cases, when the power of engines and thrusters have been made more realistic, it has meant that the power has been reduced. Often, the original developers had no data available and went for something that felt right. In more than a few cases, even though they had data from pilot cards and manufacturer's testing, the data was actually incorrect or incomplete.
As we uncover better data sources, we have modified the various characteristics.
To be honest, I can't recall if P. Angel was one of those vessels, but it may well have been. 0.5 kt sounds about right.