Is that synthetic strop the TM Vegan? I had one once, and absolutely hated it in every possible way. Worst of all, it cupped, and badly. Put it on a table, and watch closely if the edge makes good contact with the strop at all times.

Other than that, three shaves are nothing. Your problems could be anything from lack of skin stretching to your skin not having accustomed to straight shaving. I would give it a few more weeks, then see if it is still not getting better.

But one thing is almost certain: it is not the razor (or the lather, as TOBS is idiotproof to lather up).