As my technic got better my razor was getting duller ( I would refresh it from time to time, but went to long without proper refreshing). I was compensating with more pressure. After I got them re hone, my technic was better and the razor was sharp. I started to get closer shaves with less irritation.

When you switch to the shevette, you probably uses to much pressure.

My suggestion would be to resharpen your blade and try again. Provided that it was honed to shave ready in the first place.

Double O