Baffling experience with new Feather AS-D2

Hi,

I just received a Feather AS-D2 as a gift, and I tried it a few time, using the accompanying Feather platinum DE blades.
The first two times it was a good shave, although not as close as I hoped.
The third one I was really impressed, it was probably the best shave I have ever had, beside from some barbers with straight edge razor.
The baffling experience is that after that third shave, I have been unable to shave much with it anymore.
Although I did use a new blade every time (all from same batch, Feather platinum), day after day I can barely scratch the stubble, and I have to resort to my old Gillette Fusion.
I have been using exactly the same soap, brush, and blades (of course, I was using a new blade every day), using more or less the same amount of lathering.

Is it something wrong with the Feather, or perhaps the blades suddenly have become dull?
I would understand if I would have never had a good shave, but that is not the case.
Perhaps it would improve with an Ikon Open Comb Base Plate?

I am so sorry about this! I really do not want to return to the Fusion.

Sam