Hello STL,
I don't know what, if anything can be done to fix it, but I've heard that the Dynamis is too sensitive to shorts to be used for this sort of thing. I could be proved wrong on this if you get any other replies. Tonys Train Exchange in the US sells a PSRev, which is a solid state reversing module that may be the answer to your problem. I'm surprised that you haven't got any other replies.
I don't know what, if anything can be done to fix it, but I've heard that the Dynamis is too sensitive to shorts to be used for this sort of thing. I could be proved wrong on this if you get any other replies. Tonys Train Exchange in the US sells a PSRev, which is a solid state reversing module that may be the answer to your problem. I'm surprised that you haven't got any other replies.