I while since I flew one, and certainly my instinct would have been to use the sort of approach speed you are but I'd guess that in practice you are using a slightly over-slow approach speed.
You're flying with a fairly forward CG, which reduces elevator authority. Also, the AX2000 is very draggy - particularly induced drag in the roundout. This is pretty typical of microlights of the era - the Thruster, Spectrum, MW6..., all have similar characteristics.
I think I'd try flying a heavy AX2000 with a rather higher approach speed than you're using - say around 65mph. This won't add much to the landing distance because, so long as you keep the stick back through the landing roll, the induced drag will be huge and you'll still stop very quickly - but it should ensure that you get a proper 2-wheel roundout and flare. (I used to have a Spectrum which was very similar to this.)
G