I will have to look at what I'm doing but I don't think I'm dragging the edge of the strop or putting extra pressure on the edge at the end of a stroke. If anything, I tend to lift the edge off as I begin to reach the very end of the stroke, flip it and lay it down as I begin the next stroke.
I have to admit, I get a little confident today and went less observantly than normal. I'm sure it's the root cause of the problem.
As to the linen. I simply have never had luck with it. I always seem to dull the blade but, the barber manual recommends it so I'm going to try it again.
Thanks for the analysis guys, I can't shave until at least Monday moring so I will review your comments carefully.