Originalbrew, the best advice is to take everything slowly. From the stropping to the shave itself. You are wielding a knife and there is no reason to go fast.

It is not uncommon to dull a perfectly good blade while stropping, many of us have done it. Also, I was under the impression that the Thumbnail Test will dull a honed edge and really should only be used for testing the edge's evolution during honing. I may be very wrong about that but I am sure I read that somewhere.

If you have a pasted paddle, 5 to 10 laps on .5 chromium oxide or diamond paste will bring the edge back as well.

Good luck.