The Donatists really took off in North Africa with the Berber peoples.
It's specifically touching the coastal Berbers that are more romanised than their hinterlands counterparts and disappear at best with the Byzantine conquest : Donatism was essentially localized to urban centers and shore plains, the Berbers being largely let to themelves (and whom Christianization have to be nuanced : even during Byzantine period, they seems to have a relative religious autonomy, with more dynamic tribes being more Judaised than Christianized).
You simply don't have a real mention of Donatism passed the V century, so I really disagree with both "took off" and "Berbers" (if you're talking about independent Berbers, at least)
I kind of got to feel sorry for the Berbers during and after the Vandal Occupation.
On a unrelated note, why "occupation"? Vandal Kingdom was basically as legitim that its neigbours, and not an occupation in the sense they considered it as "not their own" and prey to any sort of treatment reserved to occupied aeras (and subsequant ravages).
Unless you makes reference to supposed abuses made by one or two Vandals kings on Catholics, that basically concerned orthodox clergy and let actual population out of the matters. Byzantines quite needed a reason to attack Ganseric after all, and they kinda blew it up out of proportion.
They really got screwed over by Constantinople for a while there and pretty much became independent along the limes the communities there going their own radical course.
More by Constantinople than Vandals actually : these ones were more in favour of "laisser-faire" when it came to hinterland. They took taxes, and let Berber manage themselves, including religiously (it's basically why they never really lasted in Africa). In fact, at the end of the kingdom, Vandals were the ones raided by Berbers.
So when Constantinoples comes in game, Berbers (critically the ones of the hinterland) were basically "a thing", and Byzantines had others problems than bullying them, actively at least, and allowed the constitution of tribal and confederative kingdoms.
The only ones that tried that were the Arabs, and it kinda backfired with the Berber Revolt.