Glad this worked for you, but tbh that doesn't mean it will work for anyone else.
My experience has been that either the Vita itself is a piece of s*** or QCMA is. Tbh I've never heard of this many problems with the official CMA, and the problems with QCMA are not just limited to people trying to use it with lower FW than the current, so my money is on QCMA (at least for Windows) being a buggy mess that we should probably avoid using.
Unfortunately, this is representative of a much larger problem with the Vita hacking community. FAR too many people involved it in (the users, not the hackers themselves) have the mindset "well it works for me so the problem must be on your end, and I'm not bother helping you since its clearly your own fault".