JK Flip-flop counter problem
So my first thought is it build out the un-simplified version, to ensure that your logic is correct.   I know when I was in digital circuits I typically would do that and it would work, which would show an error in the simplification.  If that is the case, slowly replace items until something doesn't work, then you have found it.   If you build it unsimplified and it doesn't work, then it may in fact be an issue with how you set up your karnaugh map.  

Again, the whole deal is process of elimination.   If you have access to another simulator maybe build it there if you are confident, but I bet it is one of the above problems.  At first glance it looks good, at least all of your don't care simplifications.