I don’t know what Islam says about this, but the Old Testament certainly speaks of God allowing enemies to do things to Israel (by which I mean biblical Israel — I don’t intend to express any position on the relationship between that country and the current day country ) for various reasons.
So, if Islam’s view of things is similar, I don’t think this would be a refutation?
(Now, to be clear, I believe that Islam is false. But I’m not convinced that “bad things are happening to them” is something they would have reason to conclude is good evidence for it being false. Of course, one could just see this as another instance of the question of theodicy (“Why does God allow bad things to happen?”), and I’m not sure this instance of it makes the question particularly more difficult to answer? Though I suppose if Islam includes claims about like, always winning or something, or always winning conditional on X,Y,Z when X,Y,Z are true, then it would contradict that.)