It's not that hard, just have Islam (and whatever states spreading it) have a hard time in North Africa, becoming even harder to gain popularity as it moves West leading to it being on the defensive as it were by the time it reaches OTL Algeria and not moving further West as it tries to colosolidate itself and not even trying to take on Morocco, since it'd be the biggest, most Advanced state of the Maghreb.
Except that morocco wasnt well organized. It was a whole mass of berber tribes and statelets.
How about this. The Ummayad dynasty falls in 685, after the foundets death in 680. His sucessor is disputed, and civil war erupts back in the heartlands of dar al-islam. Thus the expedition in 681 that 'conquered' morocco (i gather in much the same way that julius caesar 'conquered' britain, i.e. only nominally and temporarily) isnt followed up on. The civil war mean partisans of varous sides pull troops out of the borderlands, an expansion pauses.
There is enough of a presence in north africa still that control over Ifriqiya, ie the old roman province of africa, is finally consolidated, say a decade or so after otl.
Meanwhile, a charismatic and politically competant leader arises among the berbers, uniting them under his banner and that of ?christendom?. (This is functionally a second pod, because such a guy didnt exist). Then in the 700s, when islam renews its march, they face a much stronger opponent who holds them off. (How? This is darn near a third pod).
?...
I dont think its really very likely, at all, but does stop just short of asb, imo.