Yes your Satpy works the same my Satpy does. The question was whether we see the same thing with David's MSG Data Manager.
a) If MSG Data Manager (using channels 0.9 and 10.8) sees the same, then Roshydromet has a data problem.
b) If MSG Data Manager (using channels 0.9 and 10.7) sees no channel offset, then David might explain how the
channel data is geographically located on the globe. There could be a difference compared to PyTROLL/Satpy.